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<!-- DFIN ActiveDisclosure(SM) XBRL Linkbase Document - http://www.dfinsolutions.com/ -->
<!-- Creation Date      : 2022-03-10T16:28:15.5475244+00:00 -->
<!-- Version            : 5.0.1.728 -->
<!-- Package ID         : 558af53d9838426fbe84363d2fd028b6 -->
<!-- Copyright (c) 2022 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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    <link:label xml:lang="en-US" xlink:label="dei_DocumentType_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Document Type</link:label>
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    <link:label xml:lang="en-US" xlink:label="dei_DocumentFiscalYearFocus_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Fiscal Year Focus</link:label>
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    <link:label xml:lang="en-US" xlink:label="dei_DocumentFiscalPeriodFocus_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Fiscal Period Focus</link:label>
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    <link:label xml:lang="en-US" xlink:label="dei_CurrentFiscalYearEndDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current Fiscal Year End Date</link:label>
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    <link:label xml:lang="en-US" xlink:label="dei_EntityCurrentReportingStatus_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Current Reporting Status</link:label>
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    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityFilerCategory" xlink:type="locator" xlink:label="dei_EntityFilerCategory" />
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    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityFileNumber" xlink:type="locator" xlink:label="dei_EntityFileNumber" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityFileNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity File Number</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityFileNumber" xlink:to="dei_EntityFileNumber_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityFileNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity File Number</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityIncorporationStateCountryCode" xlink:type="locator" xlink:label="dei_EntityIncorporationStateCountryCode" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Incorporation, State or Country Code</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityIncorporationStateCountryCode" xlink:to="dei_EntityIncorporationStateCountryCode_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityIncorporationStateCountryCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Incorporation State Country Code</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityTaxIdentificationNumber" xlink:type="locator" xlink:label="dei_EntityTaxIdentificationNumber" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Tax Identification Number</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityTaxIdentificationNumber" xlink:to="dei_EntityTaxIdentificationNumber_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityTaxIdentificationNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Tax Identification Number</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressAddressLine1" xlink:type="locator" xlink:label="dei_EntityAddressAddressLine1" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressAddressLine1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Address Line One</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine1" xlink:to="dei_EntityAddressAddressLine1_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressAddressLine1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address Address Line1</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressAddressLine2" xlink:type="locator" xlink:label="dei_EntityAddressAddressLine2" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressAddressLine2_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Address Line Two</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressAddressLine2" xlink:to="dei_EntityAddressAddressLine2_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressAddressLine2_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address Address Line2</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressCityOrTown" xlink:type="locator" xlink:label="dei_EntityAddressCityOrTown" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, City or Town</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressCityOrTown" xlink:to="dei_EntityAddressCityOrTown_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressCityOrTown_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address City Or Town</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressStateOrProvince" xlink:type="locator" xlink:label="dei_EntityAddressStateOrProvince" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressStateOrProvince_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Entity Address, State or Province</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressStateOrProvince" xlink:to="dei_EntityAddressStateOrProvince_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressStateOrProvince_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address State Or Province</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityAddressPostalZipCode" xlink:type="locator" xlink:label="dei_EntityAddressPostalZipCode" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Address, Postal Zip Code</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityAddressPostalZipCode" xlink:to="dei_EntityAddressPostalZipCode_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityAddressPostalZipCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Address Postal Zip Code</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_CityAreaCode" xlink:type="locator" xlink:label="dei_CityAreaCode" />
    <link:label xml:lang="en-US" xlink:label="dei_CityAreaCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">City Area Code</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_CityAreaCode" xlink:to="dei_CityAreaCode_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_CityAreaCode_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">City Area Code</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_LocalPhoneNumber" xlink:type="locator" xlink:label="dei_LocalPhoneNumber" />
    <link:label xml:lang="en-US" xlink:label="dei_LocalPhoneNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Local Phone Number</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LocalPhoneNumber" xlink:to="dei_LocalPhoneNumber_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_LocalPhoneNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Local Phone Number</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentAnnualReport" xlink:type="locator" xlink:label="dei_DocumentAnnualReport" />
    <link:label xml:lang="en-US" xlink:label="dei_DocumentAnnualReport_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Annual Report</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentAnnualReport" xlink:to="dei_DocumentAnnualReport_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_DocumentAnnualReport_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Document Annual Report</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_DocumentTransitionReport" xlink:type="locator" xlink:label="dei_DocumentTransitionReport" />
    <link:label xml:lang="en-US" xlink:label="dei_DocumentTransitionReport_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Document Transition Report</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_DocumentTransitionReport" xlink:to="dei_DocumentTransitionReport_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_DocumentTransitionReport_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Document Transition Report</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityCommonStockSharesOutstanding" xlink:type="locator" xlink:label="dei_EntityCommonStockSharesOutstanding" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Entity Common Stock, Shares Outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityCommonStockSharesOutstanding" xlink:to="dei_EntityCommonStockSharesOutstanding_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityCommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Common Stock Shares Outstanding</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityPublicFloat" xlink:type="locator" xlink:label="dei_EntityPublicFloat" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityPublicFloat_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Public Float</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityPublicFloat" xlink:to="dei_EntityPublicFloat_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityPublicFloat_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Public Float</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityWellKnownSeasonedIssuer" xlink:type="locator" xlink:label="dei_EntityWellKnownSeasonedIssuer" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity Well-known Seasoned Issuer</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityWellKnownSeasonedIssuer" xlink:to="dei_EntityWellKnownSeasonedIssuer_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityWellKnownSeasonedIssuer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Well Known Seasoned Issuer</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityVoluntaryFilers" xlink:type="locator" xlink:label="dei_EntityVoluntaryFilers" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityVoluntaryFilers_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Entity Voluntary Filers</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityVoluntaryFilers" xlink:to="dei_EntityVoluntaryFilers_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityVoluntaryFilers_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity Voluntary Filers</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AuditorFirmId" xlink:type="locator" xlink:label="dei_AuditorFirmId" />
    <link:label xml:lang="en-US" xlink:label="dei_AuditorFirmId_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Auditor Firm ID</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorFirmId" xlink:to="dei_AuditorFirmId_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_AuditorFirmId_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Auditor Firm Id</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AuditorName" xlink:type="locator" xlink:label="dei_AuditorName" />
    <link:label xml:lang="en-US" xlink:label="dei_AuditorName_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Auditor Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorName" xlink:to="dei_AuditorName_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_AuditorName_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Auditor Name</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_AuditorLocation" xlink:type="locator" xlink:label="dei_AuditorLocation" />
    <link:label xml:lang="en-US" xlink:label="dei_AuditorLocation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Auditor Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_AuditorLocation" xlink:to="dei_AuditorLocation_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_AuditorLocation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Auditor Location</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress" xlink:type="locator" xlink:label="smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress" />
    <link:label xml:lang="en-US" xlink:label="smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount after accumulated depreciation, depletion and amortization of physical assets, excluding construction in progress, used in the normal conduct of business to produce goods and services and not intended for resale. Examples include, but are not limited to, land, buildings, machinery and equipment, office equipment, and furniture and fixtures.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress" xlink:to="smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_RecourseLongTermDebtCurrent" xlink:type="locator" xlink:label="smhi_RecourseLongTermDebtCurrent" />
    <link:label xml:lang="en-US" xlink:label="smhi_RecourseLongTermDebtCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recourse long term debt current.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_RecourseLongTermDebtCurrent" xlink:to="smhi_RecourseLongTermDebtCurrent_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NonRecourseLongTermDebtCurrent" xlink:type="locator" xlink:label="smhi_NonRecourseLongTermDebtCurrent" />
    <link:label xml:lang="en-US" xlink:label="smhi_NonRecourseLongTermDebtCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-recourse long term debt current.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NonRecourseLongTermDebtCurrent" xlink:to="smhi_NonRecourseLongTermDebtCurrent_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AccruedCapitalRepairAndMaintenanceExpendituresCurrent" xlink:type="locator" xlink:label="smhi_AccruedCapitalRepairAndMaintenanceExpendituresCurrent" />
    <link:label xml:lang="en-US" xlink:label="smhi_AccruedCapitalRepairAndMaintenanceExpendituresCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Carrying value as of the balance sheet date of obligations incurred through that date and payable for capital, repair and maintenance expenditures. Used to reflect the current portion of the liabilities (due within one year or within the normal operating cycle if longer).</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_AccruedCapitalRepairAndMaintenanceExpendituresCurrent" xlink:to="smhi_AccruedCapitalRepairAndMaintenanceExpendituresCurrent_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_RecourseLongTermDebtNoncurrent" xlink:type="locator" xlink:label="smhi_RecourseLongTermDebtNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="smhi_RecourseLongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recourse long term debt noncurrent.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_RecourseLongTermDebtNoncurrent" xlink:to="smhi_RecourseLongTermDebtNoncurrent_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NonRecourseLongTermDebtNoncurrent" xlink:type="locator" xlink:label="smhi_NonRecourseLongTermDebtNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="smhi_NonRecourseLongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-recourse long term debt noncurrent.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NonRecourseLongTermDebtNoncurrent" xlink:to="smhi_NonRecourseLongTermDebtNoncurrent_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfFinancialPositionAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfFinancialPositionAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementOfFinancialPositionAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Of Financial Position [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfFinancialPositionAbstract" xlink:to="us-gaap_StatementOfFinancialPositionAbstract_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsAbstract" xlink:type="locator" xlink:label="us-gaap_AssetsAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ASSETS</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsAbstract" xlink:to="us-gaap_AssetsAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrentAbstract" xlink:type="locator" xlink:label="us-gaap_AssetsCurrentAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current Assets:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrentAbstract" xlink:to="us-gaap_AssetsCurrentAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsCurrentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets Current [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:type="locator" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash and cash equivalents</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashAndCashEquivalentsAtCarryingValue" xlink:to="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CashAndCashEquivalentsAtCarryingValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash And Cash Equivalents At Carrying Value</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedCashAndCashEquivalents" xlink:type="locator" xlink:label="us-gaap_RestrictedCashAndCashEquivalents" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedCashAndCashEquivalents_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReceivablesAbstract" xlink:type="locator" xlink:label="us-gaap_ReceivablesAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ReceivablesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Receivables:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ReceivablesAbstract" xlink:to="us-gaap_ReceivablesAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ReceivablesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Receivables [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsReceivableNetCurrent" xlink:type="locator" xlink:label="us-gaap_AccountsReceivableNetCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccountsReceivableNetCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trade, net of allowance for credit loss accounts of $1,312 and $582 in 2021 and 2020, respectively</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsReceivableNetCurrent" xlink:to="us-gaap_AccountsReceivableNetCurrent_lbl" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherReceivablesNetCurrent" xlink:type="locator" xlink:label="us-gaap_OtherReceivablesNetCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherReceivablesNetCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherReceivablesNetCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Receivables Net Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DueFromAffiliateCurrent" xlink:type="locator" xlink:label="us-gaap_DueFromAffiliateCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DueFromAffiliateCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Receivable from SEACOR Holdings</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DueFromAffiliateCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Due From Affiliate Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxesReceivable" xlink:type="locator" xlink:label="us-gaap_IncomeTaxesReceivable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxesReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax receivable</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxesReceivable" xlink:to="us-gaap_IncomeTaxesReceivable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxesReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Taxes Receivable</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryNet" xlink:type="locator" xlink:label="us-gaap_InventoryNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InventoryNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventories</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_InventoryNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Inventory Net</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:type="locator" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid expenses and other</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrepaidExpenseAndOtherAssetsCurrent" xlink:to="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PrepaidExpenseAndOtherAssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Expense And Other Assets Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:type="locator" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assets held for sale</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:to="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets Of Disposal Group Including Discontinued Operation Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsCurrent" xlink:type="locator" xlink:label="us-gaap_AssetsCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsCurrent" xlink:to="us-gaap_AssetsCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentAbstract" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and Equipment:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentAbstract" xlink:to="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentGross" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Historical cost</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Gross</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedDepreciationDepletionAndAmortizationPropertyPlantAndEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Accumulated depreciation</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Property and equipment</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Excluding Construction In Progress</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Construction in progress</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConstructionInProgressGross" xlink:to="us-gaap_ConstructionInProgressGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConstructionInProgressGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Construction In Progress Gross</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net property and equipment</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Net</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseRightOfUseAsset_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use asset - operating leases</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseRightOfUseAsset_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use asset - finance leases</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures" xlink:type="locator" xlink:label="us-gaap_InvestmentsInAffiliatesSubsidiariesAssociatesAndJointVentures" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherAssetsNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other assets</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_Assets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total assets</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current Liabilities:</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesCurrentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Current [Abstract]</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current portion of operating lease liabilities</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Liability Current</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current portion of finance lease liabilities</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtCurrentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current portion of long-term debt:</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtCurrentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Current [Abstract]</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_NonRecourseLongTermDebtCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-recourse</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NonRecourseLongTermDebtCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Non Recourse Long Term Debt Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable and accrued expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent" xlink:to="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccountsPayableAndAccruedLiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accounts Payable And Accrued Liabilities Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DueToAffiliateCurrent" xlink:type="locator" xlink:label="us-gaap_DueToAffiliateCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DueToAffiliateCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Due to SEACOR Holdings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DueToAffiliateCurrent" xlink:to="us-gaap_DueToAffiliateCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DueToAffiliateCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Due To Affiliate Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued wages and benefits</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeRelatedLiabilitiesCurrent" xlink:to="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeRelatedLiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Employee Related Liabilities Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestAndDividendsPayableCurrent" xlink:type="locator" xlink:label="us-gaap_InterestAndDividendsPayableCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestAndDividendsPayableCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestAndDividendsPayableCurrent" xlink:to="us-gaap_InterestAndDividendsPayableCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestAndDividendsPayableCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest And Dividends Payable Current</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AccruedCapitalRepairAndMaintenanceExpendituresCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued capital, repair and maintenance expenditures</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AccruedCapitalRepairAndMaintenanceExpendituresCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Capital Repair And Maintenance Expenditures Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerLiabilityCurrent" xlink:type="locator" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred revenue and unearned revenue</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityCurrent" xlink:to="us-gaap_ContractWithCustomerLiabilityCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiabilityCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Liability Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedInsuranceCurrent" xlink:type="locator" xlink:label="us-gaap_AccruedInsuranceCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccruedInsuranceCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued insurance deductibles and premiums</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedInsuranceCurrent" xlink:to="us-gaap_AccruedInsuranceCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccruedInsuranceCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Insurance Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccruedProfessionalFeesCurrent" xlink:type="locator" xlink:label="us-gaap_AccruedProfessionalFeesCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccruedProfessionalFeesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accrued professional fees</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccruedProfessionalFeesCurrent" xlink:to="us-gaap_AccruedProfessionalFeesCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccruedProfessionalFeesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accrued Professional Fees Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilitiesCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeLiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivatives</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeLiabilitiesCurrent" xlink:to="us-gaap_DerivativeLiabilitiesCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeLiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Liabilities Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other current liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesCurrent" xlink:to="us-gaap_OtherLiabilitiesCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherLiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liabilities held for sale</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent" xlink:to="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Of Disposal Group Including Discontinued Operation Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesCurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total current liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesCurrent" xlink:to="us-gaap_LiabilitiesCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term operating lease liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilityNoncurrent" xlink:to="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilityNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Liability Noncurrent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term finance lease liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityNoncurrent" xlink:to="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Noncurrent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtNoncurrentAbstract" xlink:type="locator" xlink:label="us-gaap_LongTermDebtNoncurrentAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtNoncurrentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term Debt:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtNoncurrentAbstract" xlink:to="us-gaap_LongTermDebtNoncurrentAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtNoncurrentAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Noncurrent [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_RecourseLongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recourse</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_RecourseLongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recourse Long Term Debt Noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NonRecourseLongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-recourse</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NonRecourseLongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Non Recourse Long Term Debt Noncurrent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilitiesNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeLiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conversion option liability on convertible senior notes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeLiabilitiesNoncurrent" xlink:to="us-gaap_DerivativeLiabilitiesNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeLiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Liabilities Noncurrent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:type="locator" xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred income taxes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredIncomeTaxLiabilitiesNet" xlink:to="us-gaap_DeferredIncomeTaxLiabilitiesNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredIncomeTaxLiabilitiesNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Income Tax Liabilities Net</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherLiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_OtherLiabilitiesNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred gains and other liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherLiabilitiesNoncurrent" xlink:to="us-gaap_OtherLiabilitiesNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherLiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Liabilities Noncurrent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Liabilities" xlink:type="locator" xlink:label="us-gaap_Liabilities" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Liabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Liabilities" xlink:to="us-gaap_Liabilities_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Liabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterestAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity:</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityAbstract" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Marine Holdings Inc. stockholders&apos; equity:</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockValue" xlink:type="locator" xlink:label="us-gaap_CommonStockValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, $.01 par value, 60,000,000 shares authorized; 26,120,124 and 23,504,050 shares issued in 2021 and 2020, respectively</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Value</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_AdditionalPaidInCapitalCommonStock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Additional Paid In Capital Common Stock</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsAccumulatedDeficit" xlink:type="locator" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated deficit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetainedEarningsAccumulatedDeficit" xlink:to="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetainedEarningsAccumulatedDeficit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Retained Earnings Accumulated Deficit</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockValue" xlink:type="locator" xlink:label="us-gaap_TreasuryStockValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Shares held in treasury of 127,887 and 73,284 in 2021 and 2020, respectively, at cost</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockValue" xlink:to="us-gaap_TreasuryStockValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock Value</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:type="locator" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated other comprehensive income, net of tax</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Other Comprehensive Income Loss Net Of Tax</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquity" xlink:type="locator" xlink:label="us-gaap_StockholdersEquity" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total stockholders equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquity" xlink:to="us-gaap_StockholdersEquity_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders Equity</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MinorityInterest" xlink:type="locator" xlink:label="us-gaap_MinorityInterest" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Noncontrolling interests in subsidiaries</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterest" xlink:to="us-gaap_MinorityInterest_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Minority Interest</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders Equity Including Portion Attributable To Noncontrolling Interest</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesAndStockholdersEquity" xlink:type="locator" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total liabilities and equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesAndStockholdersEquity" xlink:to="us-gaap_LiabilitiesAndStockholdersEquity_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesAndStockholdersEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities And Stockholders Equity</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:type="locator" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Trade receivables, allowance for credit loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent" xlink:to="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AllowanceForDoubtfulAccountsReceivableCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Allowance For Doubtful Accounts Receivable Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockParOrStatedValuePerShare" xlink:type="locator" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, par value (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockParOrStatedValuePerShare" xlink:to="us-gaap_CommonStockParOrStatedValuePerShare_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockParOrStatedValuePerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Par Or Stated Value Per Share</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesAuthorized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares authorized (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesAuthorized" xlink:to="us-gaap_CommonStockSharesAuthorized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Shares Authorized</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockSharesIssued" xlink:type="locator" xlink:label="us-gaap_CommonStockSharesIssued" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock, shares issued (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockSharesIssued" xlink:to="us-gaap_CommonStockSharesIssued_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Shares Issued</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockShares" xlink:type="locator" xlink:label="us-gaap_TreasuryStockShares" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockShares_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Shares held in treasury (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockShares" xlink:to="us-gaap_TreasuryStockShares_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockShares_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock Shares</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LeaseExpense" xlink:type="locator" xlink:label="smhi_LeaseExpense" />
    <link:label xml:lang="en-US" xlink:label="smhi_LeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of lease expense not specifice to general day to day operations.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LeaseExpense" xlink:to="smhi_LeaseExpense_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_GuaranteeFeesRelatedParty" xlink:type="locator" xlink:label="smhi_GuaranteeFeesRelatedParty" />
    <link:label xml:lang="en-US" xlink:label="smhi_GuaranteeFeesRelatedParty_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of guarantee fees attributable to a related party.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_GuaranteeFeesRelatedParty" xlink:to="smhi_GuaranteeFeesRelatedParty_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_GainLossFromReturnOfInvestmentsAndOtherNet" xlink:type="locator" xlink:label="smhi_GainLossFromReturnOfInvestmentsAndOtherNet" />
    <link:label xml:lang="en-US" xlink:label="smhi_GainLossFromReturnOfInvestmentsAndOtherNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Gain (loss) from return of investments and other net.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_GainLossFromReturnOfInvestmentsAndOtherNet" xlink:to="smhi_GainLossFromReturnOfInvestmentsAndOtherNet_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_IncomeLossFromContinuingOperationsBeforeEquityMethodInvestmentsAndNoncontrollingInterestAfterTax" xlink:type="locator" xlink:label="smhi_IncomeLossFromContinuingOperationsBeforeEquityMethodInvestmentsAndNoncontrollingInterestAfterTax" />
    <link:label xml:lang="en-US" xlink:label="smhi_IncomeLossFromContinuingOperationsBeforeEquityMethodInvestmentsAndNoncontrollingInterestAfterTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of income (loss) from continuing operations before income (loss) from equity method investments and income (loss) attributable to noncontrolling interest, but after tax of income (loss) from continuing operations.</link:label>
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_IncomeLossFromContinuingOperationsNetOfTaxPerBasicAndDilutedShareAbstract" xlink:type="locator" xlink:label="smhi_IncomeLossFromContinuingOperationsNetOfTaxPerBasicAndDilutedShareAbstract" />
    <link:label xml:lang="en-US" xlink:label="smhi_IncomeLossFromContinuingOperationsNetOfTaxPerBasicAndDilutedShareAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Income (loss) from continuing operations net of tax per basic and diluted share.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_IncomeLossFromContinuingOperationsNetOfTaxPerBasicAndDilutedShareAbstract" xlink:to="smhi_IncomeLossFromContinuingOperationsNetOfTaxPerBasicAndDilutedShareAbstract_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementAbstract" xlink:type="locator" xlink:label="us-gaap_IncomeStatementAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementAbstract" xlink:to="us-gaap_IncomeStatementAbstract_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:type="locator" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Revenues</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax" xlink:to="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revenue From Contract With Customer Including Assessed Tax</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostsAndExpensesAbstract" xlink:type="locator" xlink:label="us-gaap_CostsAndExpensesAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CostsAndExpensesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Costs and Expenses:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostsAndExpensesAbstract" xlink:to="us-gaap_CostsAndExpensesAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CostsAndExpensesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Costs And Expenses [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingCostsAndExpenses" xlink:type="locator" xlink:label="us-gaap_OperatingCostsAndExpenses" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingCostsAndExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingCostsAndExpenses" xlink:to="us-gaap_OperatingCostsAndExpenses_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingCostsAndExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Costs And Expenses</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeneralAndAdministrativeExpense" xlink:type="locator" xlink:label="us-gaap_GeneralAndAdministrativeExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Administrative and general</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_GeneralAndAdministrativeExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">General And Administrative Expense</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease expense</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lease Expense</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DepreciationDepletionAndAmortization" xlink:type="locator" xlink:label="us-gaap_DepreciationDepletionAndAmortization" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation and amortization</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DepreciationDepletionAndAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation Depletion And Amortization</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CostsAndExpenses" xlink:type="locator" xlink:label="us-gaap_CostsAndExpenses" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CostsAndExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Costs and Expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CostsAndExpenses" xlink:to="us-gaap_CostsAndExpenses_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CostsAndExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Costs And Expenses</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges" xlink:type="locator" xlink:label="us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gains (Losses) on Asset Dispositions and Impairments, Net</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_ComprehensiveIncomeNetOfTaxIncludingPortionAttributableToNoncontrollingInterest_lbl" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ComprehensiveIncomeNetOfTax" xlink:type="locator" xlink:label="us-gaap_ComprehensiveIncomeNetOfTax" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfOwnedCompaniesDerivativeLossesOnCashFlowHedgesReclassificationToEquityInEarnings" xlink:type="locator" xlink:label="smhi_PercentageOfOwnedCompaniesDerivativeLossesOnCashFlowHedgesReclassificationToEquityInEarnings" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_StockRepurchasedDuringPeriodValueExerciseOfWarrants" xlink:type="locator" xlink:label="smhi_StockRepurchasedDuringPeriodValueExerciseOfWarrants" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_StockGrantedDuringPeriodSharesShareBasedCompensation" xlink:type="locator" xlink:label="smhi_StockGrantedDuringPeriodSharesShareBasedCompensation" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_SaleOfStandbySafetyFleet" xlink:type="locator" xlink:label="smhi_SaleOfStandbySafetyFleet" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SaleOfStandbySafetyFleet" xlink:to="smhi_SaleOfStandbySafetyFleet_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DissolutionOfEntity" xlink:type="locator" xlink:label="smhi_DissolutionOfEntity" />
    <link:label xml:lang="en-US" xlink:label="smhi_DissolutionOfEntity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Dissolution of entity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DissolutionOfEntity" xlink:to="smhi_DissolutionOfEntity_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CancellationOfGrantsAndOptionsShares" xlink:type="locator" xlink:label="smhi_CancellationOfGrantsAndOptionsShares" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CancellationOfGrantsAndOptionsShares" xlink:to="smhi_CancellationOfGrantsAndOptionsShares_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AdjustmentToAdditionalPaidInCapitalValueCancellationOfGrantsAndOptions" xlink:type="locator" xlink:label="smhi_AdjustmentToAdditionalPaidInCapitalValueCancellationOfGrantsAndOptions" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_SaleOfWindcatWorkboats" xlink:type="locator" xlink:label="smhi_SaleOfWindcatWorkboats" />
    <link:label xml:lang="en-US" xlink:label="smhi_SaleOfWindcatWorkboats_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Sale of Windcat Workboats.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SaleOfWindcatWorkboats" xlink:to="smhi_SaleOfWindcatWorkboats_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfStockholdersEquityAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfStockholdersEquityAbstract" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementEquityComponentsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Other Comprehensive Income (Loss) [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Component</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityComponentDomain" xlink:to="us-gaap_EquityComponentDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityComponentDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Component [Domain]</link:label>
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockMember" xlink:to="us-gaap_CommonStockMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock [Member]</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockMember" xlink:type="locator" xlink:label="us-gaap_TreasuryStockMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Treasury Stock [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockMember" xlink:to="us-gaap_TreasuryStockMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetainedEarningsMember" xlink:type="locator" xlink:label="us-gaap_RetainedEarningsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetainedEarningsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retained Earnings [Member]</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeMember" xlink:type="locator" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Other Comprehensive Income [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_NoncontrollingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-Controlling Interests In Subsidiaries [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_NoncontrollingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Noncontrolling Interest [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:label="srt_RestatementAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revision of Prior Period</link:label>
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    <link:label xml:lang="en-US" xlink:label="srt_RestatementDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revision of Prior Period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RestatementDomain" xlink:to="srt_RestatementDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_RestatementDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Restatement [Domain]</link:label>
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    <link:label xml:lang="en-US" xlink:label="srt_ScenarioPreviouslyReportedMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Previously Reported [Member]</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueNewIssues_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of common stock</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Issuance of Common Stock (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesNewIssues" xlink:to="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares New Issues</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted stock grants</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Value Restricted Stock Award Gross</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted stock grants (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares Restricted Stock Award Gross</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Cancellation of restricted stock grants</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures" xlink:to="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueRestrictedStockAwardForfeitures_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Value Restricted Stock Award Forfeitures</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Cancellation of restricted stock grants (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited" xlink:to="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesRestrictedStockAwardForfeited_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares Restricted Stock Award Forfeited</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AdjustmentToAdditionalPaidInCapitalValueCancellationOfGrantsAndOptions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cancellation of grants and options</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AdjustmentToAdditionalPaidInCapitalValueCancellationOfGrantsAndOptions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Adjustment To Additional Paid In Capital Value Cancellation Of Grants And Options</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CancellationOfGrantsAndOptionsShares_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cancellation of grants and options (in shares)</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CancellationOfGrantsAndOptionsShares_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cancellation Of Grants And Options Shares</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:type="locator" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of employee share awards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue" xlink:to="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AdjustmentsToAdditionalPaidInCapitalSharebasedCompensationRequisiteServicePeriodRecognitionValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments To Additional Paid In Capital Sharebased Compensation Requisite Service Period Recognition Value</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of employee share awards (Shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation" xlink:to="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesShareBasedCompensation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares Share Based Compensation</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise of options</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueStockOptionsExercised_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Value Stock Options Exercised</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise of options (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised" xlink:to="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares Stock Options Exercised</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_StockRepurchasedDuringPeriodValueExerciseOfWarrants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise of warrants</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_StockRepurchasedDuringPeriodValueExerciseOfWarrants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Repurchased During Period Value Exercise Of Warrants</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_StockRepurchasedDuringPeriodSharesExerciseOfWarrants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercise of Warrants (in shares)</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_StockRepurchasedDuringPeriodSharesExerciseOfWarrants_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Repurchased During Period Shares Exercise Of Warrants</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:type="locator" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Restricted stock vesting</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockValueAcquiredCostMethod" xlink:to="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockValueAcquiredCostMethod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock Value Acquired Cost Method</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TreasuryStockSharesAcquired" xlink:type="locator" xlink:label="us-gaap_TreasuryStockSharesAcquired" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockSharesAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Restricted stock vesting (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TreasuryStockSharesAcquired" xlink:to="us-gaap_TreasuryStockSharesAcquired_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TreasuryStockSharesAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Treasury Stock Shares Acquired</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Director share awards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueIssuedForServices" xlink:to="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueIssuedForServices_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Value Issued For Services</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Director share awards (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices" xlink:to="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesIssuedForServices_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares Issued For Services</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockGrantedDuringPeriodValueSharebasedCompensation" xlink:type="locator" xlink:label="us-gaap_StockGrantedDuringPeriodValueSharebasedCompensation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockGrantedDuringPeriodValueSharebasedCompensation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Acquisition of consolidated joint venture</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockGrantedDuringPeriodValueSharebasedCompensation" xlink:to="us-gaap_StockGrantedDuringPeriodValueSharebasedCompensation_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockGrantedDuringPeriodValueSharebasedCompensation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Granted During Period Value Sharebased Compensation</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_StockGrantedDuringPeriodSharesShareBasedCompensation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Acquisition of consolidated joint venture (in shares)</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_StockGrantedDuringPeriodSharesShareBasedCompensation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Granted During Period Shares Share Based Compensation</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition of 50% or less owned company</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodValueAcquisitions" xlink:to="us-gaap_StockIssuedDuringPeriodValueAcquisitions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodValueAcquisitions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Value Acquisitions</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:type="locator" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquisition of 50% or less owned company (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockIssuedDuringPeriodSharesAcquisitions" xlink:to="us-gaap_StockIssuedDuringPeriodSharesAcquisitions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesAcquisitions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares Acquisitions</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SaleOfWindcatWorkboats_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Sale of Windcat Workboats</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SaleOfWindcatWorkboats_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sale Of Windcat Workboats</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SaleOfStandbySafetyFleet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Sale of Standby Safety Fleet</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SaleOfStandbySafetyFleet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sale Of Standby Safety Fleet</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DissolutionOfEntity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dissolution of entity</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DissolutionOfEntity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Dissolution Of Entity</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherComprehensiveIncomeLossNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other comprehensive income</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Balance</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Balance (in shares)</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OwnershipPercentage" xlink:type="locator" xlink:label="smhi_OwnershipPercentage" />
    <link:label xml:lang="en-US" xlink:label="smhi_OwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the ownership percentage of a consolidated entity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OwnershipPercentage" xlink:to="smhi_OwnershipPercentage_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeAxis" xlink:type="locator" xlink:label="srt_RangeAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_RangeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statistical Measurement</link:label>
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    <link:label xml:lang="en-US" xlink:label="srt_RangeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Range [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RangeMember" xlink:type="locator" xlink:label="srt_RangeMember" />
    <link:label xml:lang="en-US" xlink:label="srt_RangeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statistical Measurement</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RangeMember" xlink:to="srt_RangeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_RangeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Range [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MaximumMember" xlink:type="locator" xlink:label="srt_MaximumMember" />
    <link:label xml:lang="en-US" xlink:label="srt_MaximumMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Maximum</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MaximumMember" xlink:to="srt_MaximumMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_MaximumMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Maximum [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MinimumMember" xlink:type="locator" xlink:label="srt_MinimumMember" />
    <link:label xml:lang="en-US" xlink:label="srt_MinimumMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minimum [Member]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MinimumMember" xlink:to="srt_MinimumMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_MinimumMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Minimum [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Ownership Percentage</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Ownership Percentage</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_GainLossFromReturnOfInvestments" xlink:type="locator" xlink:label="smhi_GainLossFromReturnOfInvestments" />
    <link:label xml:lang="en-US" xlink:label="smhi_GainLossFromReturnOfInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Gain (loss) from return of investments.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_GainLossFromReturnOfInvestments" xlink:to="smhi_GainLossFromReturnOfInvestments_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromInterestOnFinanceLeases" xlink:type="locator" xlink:label="smhi_ProceedsFromInterestOnFinanceLeases" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromInterestOnFinanceLeases_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from interest on finance leases.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromInterestOnFinanceLeases" xlink:to="smhi_ProceedsFromInterestOnFinanceLeases_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PaymentsForProceedsFromDerivativeInstrumentsOperatingActivities" xlink:type="locator" xlink:label="smhi_PaymentsForProceedsFromDerivativeInstrumentsOperatingActivities" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForProceedsFromDerivativeInstrumentsOperatingActivities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The net amount of cash paid for or received to settle derivatives during the period not designated as hedges.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PaymentsForProceedsFromDerivativeInstrumentsOperatingActivities" xlink:to="smhi_PaymentsForProceedsFromDerivativeInstrumentsOperatingActivities_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PaymentsForProceedsFromCashImpactOfSaleOfERRVFleet" xlink:type="locator" xlink:label="smhi_PaymentsForProceedsFromCashImpactOfSaleOfERRVFleet" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForProceedsFromCashImpactOfSaleOfERRVFleet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Payments for proceeds from cash impact of sale of ERRV fleet.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PaymentsForProceedsFromCashImpactOfSaleOfERRVFleet" xlink:to="smhi_PaymentsForProceedsFromCashImpactOfSaleOfERRVFleet_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PaymentsToAcquireProceedsFromDivestitureInterestInJointVenture" xlink:type="locator" xlink:label="smhi_PaymentsToAcquireProceedsFromDivestitureInterestInJointVenture" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsToAcquireProceedsFromDivestitureInterestInJointVenture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Payments to acquire proceeds from divestiture interest in joint venture.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PaymentsToAcquireProceedsFromDivestitureInterestInJointVenture" xlink:to="smhi_PaymentsToAcquireProceedsFromDivestitureInterestInJointVenture_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromSaleOfPropertyNetOfTransactionCostsAndCashSold" xlink:type="locator" xlink:label="smhi_ProceedsFromSaleOfPropertyNetOfTransactionCostsAndCashSold" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyNetOfTransactionCostsAndCashSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from sale of property net of transaction costs and cash sold.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromSaleOfPropertyNetOfTransactionCostsAndCashSold" xlink:to="smhi_ProceedsFromSaleOfPropertyNetOfTransactionCostsAndCashSold_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromInvestmentsDistributionReturnOfCapital" xlink:type="locator" xlink:label="smhi_ProceedsFromInvestmentsDistributionReturnOfCapital" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromInvestmentsDistributionReturnOfCapital_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The cash inflow from investments 50% or less owned due to distributions classified as return of capital.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromInvestmentsDistributionReturnOfCapital" xlink:to="smhi_ProceedsFromInvestmentsDistributionReturnOfCapital_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ConstructionReserveFundsTransferredToShortTermCash" xlink:type="locator" xlink:label="smhi_ConstructionReserveFundsTransferredToShortTermCash" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundsTransferredToShortTermCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Construction reserve funds transferred to short term cash.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ConstructionReserveFundsTransferredToShortTermCash" xlink:to="smhi_ConstructionReserveFundsTransferredToShortTermCash_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromStockOptionsAndWarrantsExercised" xlink:type="locator" xlink:label="smhi_ProceedsFromStockOptionsAndWarrantsExercised" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromStockOptionsAndWarrantsExercised_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of cash inflow from exercise of stock options and warrants granted.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromStockOptionsAndWarrantsExercised" xlink:to="smhi_ProceedsFromStockOptionsAndWarrantsExercised_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PaymentToSubsidiarySharesFromNoncontrollingInterests" xlink:type="locator" xlink:label="smhi_PaymentToSubsidiarySharesFromNoncontrollingInterests" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentToSubsidiarySharesFromNoncontrollingInterests_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Payment to subsidiary shares from noncontrolling interests.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PaymentToSubsidiarySharesFromNoncontrollingInterests" xlink:to="smhi_PaymentToSubsidiarySharesFromNoncontrollingInterests_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseContinuingOperationsIncludingExchangeRateEffect" xlink:type="locator" xlink:label="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseContinuingOperationsIncludingExchangeRateEffect" />
    <link:label xml:lang="en-US" xlink:label="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseContinuingOperationsIncludingExchangeRateEffect_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash, cash equivalents, restricted cash and restricted cash equivalents, period increase (decrease), continuing operations, including exchange rate effect.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseContinuingOperationsIncludingExchangeRateEffect" xlink:to="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseContinuingOperationsIncludingExchangeRateEffect_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseDiscontinuedOperationsIncludingExchangeRateEffect" xlink:type="locator" xlink:label="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseDiscontinuedOperationsIncludingExchangeRateEffect" />
    <link:label xml:lang="en-US" xlink:label="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseDiscontinuedOperationsIncludingExchangeRateEffect_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash, cash equivalents, restricted cash and restricted cash equivalents, period increase (decrease), discontinued operations, including exchange rate effect.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseDiscontinuedOperationsIncludingExchangeRateEffect" xlink:to="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPeriodIncreaseDecreaseDiscontinuedOperationsIncludingExchangeRateEffect_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NoncashDecreaseInJointVentureInvestmentsRelatedToAcquisition" xlink:type="locator" xlink:label="smhi_NoncashDecreaseInJointVentureInvestmentsRelatedToAcquisition" />
    <link:label xml:lang="en-US" xlink:label="smhi_NoncashDecreaseInJointVentureInvestmentsRelatedToAcquisition_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Noncash decrease in joint venture investments related to acquisition.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NoncashDecreaseInJointVentureInvestmentsRelatedToAcquisition" xlink:to="smhi_NoncashDecreaseInJointVentureInvestmentsRelatedToAcquisition_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NoncashIncreaseInLongTermDebtRelatedToAssetPurchases" xlink:type="locator" xlink:label="smhi_NoncashIncreaseInLongTermDebtRelatedToAssetPurchases" />
    <link:label xml:lang="en-US" xlink:label="smhi_NoncashIncreaseInLongTermDebtRelatedToAssetPurchases_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Noncash increase in long term debt related to asset purchases.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NoncashIncreaseInLongTermDebtRelatedToAssetPurchases" xlink:to="smhi_NoncashIncreaseInLongTermDebtRelatedToAssetPurchases_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_IncreaseDecreaseInDebtRelatedToDebtSettlement" xlink:type="locator" xlink:label="smhi_IncreaseDecreaseInDebtRelatedToDebtSettlement" />
    <link:label xml:lang="en-US" xlink:label="smhi_IncreaseDecreaseInDebtRelatedToDebtSettlement_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase decrease in debt related to debt settlement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_IncreaseDecreaseInDebtRelatedToDebtSettlement" xlink:to="smhi_IncreaseDecreaseInDebtRelatedToDebtSettlement_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_IncreaseDecreaseInCapitalExpendituresInAccountsPayableAndAccruedLiabilities" xlink:type="locator" xlink:label="smhi_IncreaseDecreaseInCapitalExpendituresInAccountsPayableAndAccruedLiabilities" />
    <link:label xml:lang="en-US" xlink:label="smhi_IncreaseDecreaseInCapitalExpendituresInAccountsPayableAndAccruedLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Increase (Decrease) in capital expenditures in accounts payable and accrued liabilities.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_IncreaseDecreaseInCapitalExpendituresInAccountsPayableAndAccruedLiabilities" xlink:to="smhi_IncreaseDecreaseInCapitalExpendituresInAccountsPayableAndAccruedLiabilities_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_RecognitionOfNewRightOfUseAssetOperatingLeases" xlink:type="locator" xlink:label="smhi_RecognitionOfNewRightOfUseAssetOperatingLeases" />
    <link:label xml:lang="en-US" xlink:label="smhi_RecognitionOfNewRightOfUseAssetOperatingLeases_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Recognition of new right-of-use asset - operating leases.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_RecognitionOfNewRightOfUseAssetOperatingLeases" xlink:to="smhi_RecognitionOfNewRightOfUseAssetOperatingLeases_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOfCashFlowsAbstract" xlink:type="locator" xlink:label="us-gaap_StatementOfCashFlowsAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementOfCashFlowsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Of Cash Flows [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOfCashFlowsAbstract" xlink:to="us-gaap_StatementOfCashFlowsAbstract_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:type="locator" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Disposal Group Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis" xlink:to="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:type="locator" xlink:label="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Disposal Group Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain" xlink:to="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupsIncludingDiscontinuedOperationsNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Groups Including Discontinued Operations Name [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_WindcatWorkboatsMember" xlink:type="locator" xlink:label="smhi_WindcatWorkboatsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Windcat Workboats.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_WindcatWorkboatsMember" xlink:to="smhi_WindcatWorkboatsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Windcat Workboats</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Windcat Workboats [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_BostonPutfordOffshoreSafetyLimitedMember" xlink:type="locator" xlink:label="smhi_BostonPutfordOffshoreSafetyLimitedMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_BostonPutfordOffshoreSafetyLimitedMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Boston Putford Offshore Safety Limited.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_BostonPutfordOffshoreSafetyLimitedMember" xlink:to="smhi_BostonPutfordOffshoreSafetyLimitedMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_BostonPutfordOffshoreSafetyLimitedMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Boston Putford Offshore Safety</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BostonPutfordOffshoreSafetyLimitedMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Boston Putford Offshore Safety Limited [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ERRVFleetBusinessMember" xlink:type="locator" xlink:label="smhi_ERRVFleetBusinessMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ERRVFleetBusinessMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">ERRV fleet business.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ERRVFleetBusinessMember" xlink:to="smhi_ERRVFleetBusinessMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ERRVFleetBusinessMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ERRV Fleet Business</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ERRVFleetBusinessMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">E R R V Fleet Business [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Flows from Continuing Operating Activities:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract" xlink:to="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperationsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Net Cash Provided By Used In Operating Activities Continuing Operations [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:type="locator" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net Income (Loss)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest" xlink:to="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Loss From Continuing Operations Including Portion Attributable To Noncontrolling Interest</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensation" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stock-based compensation expense</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AmortizationOfDebtDiscountPremium" xlink:type="locator" xlink:label="us-gaap_AmortizationOfDebtDiscountPremium" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AmortizationOfDebtDiscountPremium_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt discount amortization</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AmortizationOfDebtDiscountPremium" xlink:to="us-gaap_AmortizationOfDebtDiscountPremium_lbl" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProvisionForDoubtfulAccounts" xlink:type="locator" xlink:label="us-gaap_ProvisionForDoubtfulAccounts" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProvisionForDoubtfulAccounts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Allowance for credit losses</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnDispositionOfAssets1" xlink:type="locator" xlink:label="us-gaap_GainLossOnDispositionOfAssets1" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost" xlink:type="locator" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebtBeforeWriteOffOfDeferredDebtIssuanceCost" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnDerivativeInstrumentsNetPretax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Derivative gains</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromInterestOnFinanceLeases_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest on finance lease</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForProceedsFromDerivativeInstrumentsOperatingActivities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Cash settlement payments on derivative transactions, net</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignCurrencyTransactionGainLossBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Currency losses</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Equity (earnings) losses</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromDividendsReceived" xlink:type="locator" xlink:label="us-gaap_ProceedsFromDividendsReceived" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromDividendsReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Dividends received from equity investees</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromDividendsReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Dividends Received</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncreaseDecreaseInOperatingCapitalAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Changes in Operating Assets and Liabilities:</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncreaseDecreaseInPrepaidDeferredExpenseAndOtherAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Other assets</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" xlink:type="locator" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncreaseDecreaseInAccountsPayableAndAccruedLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounts payable and accrued liabilities</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInOperatingActivitiesContinuingOperations" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" xlink:type="locator" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetCashProvidedByUsedInInvestingActivitiesContinuingOperationsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Flows from Continuing Investing Activities:</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquirePropertyPlantAndEquipment" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from disposition of property and equipment</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForProceedsFromCashImpactOfSaleOfERRVFleet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Cash impact of sale of ERRV fleet</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsToAcquireProceedsFromDivestitureInterestInJointVenture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchase of subsidiary from joint venture</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyNetOfTransactionCostsAndCashSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from sale of Windcat Workboats, net of transaction costs and cash sold</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTextBlock" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentTextBlock" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfRestructuringAndRelatedCostsTextBlock" />
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    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" xlink:type="locator" xlink:label="srt_ScheduleOfEquityMethodInvestmentEquityMethodInvesteeNameAxis" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_OSVPartnersMember" xlink:type="locator" xlink:label="smhi_OSVPartnersMember" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_SheduleOfVesselAcquiredAndDisposedOfTableTextBlock" xlink:type="locator" xlink:label="smhi_SheduleOfVesselAcquiredAndDisposedOfTableTextBlock" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentsTextBlock" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentsTextBlock" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentsTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investments [Text Block]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LesseeOperatingAndFinanceLeaseLiabilityMaturityTableTextBlock" xlink:type="locator" xlink:label="smhi_LesseeOperatingAndFinanceLeaseLiabilityMaturityTableTextBlock" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Summary of Components of Leases Expense</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseCostTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lease Cost Table [Text Block]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock" xlink:type="locator" xlink:label="smhi_ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_ScheduleOfOtherInformationRelatedToLeasesTableTextBlock" xlink:type="locator" xlink:label="smhi_ScheduleOfOtherInformationRelatedToLeasesTableTextBlock" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDebtInstrumentsTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfDebtInstrumentsTextBlock" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfMaturitiesOfLongTermDebtTableTextBlock" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDebtorTroubledDebtRestructuringCurrentPeriodTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfDebtorTroubledDebtRestructuringCurrentPeriodTextBlock" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfIncomeBeforeIncomeTaxDomesticAndForeignTableTextBlock" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock" xlink:to="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsInStatementOfFinancialPositionFairValueTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Derivative Instruments In Statement Of Financial Position Fair Value [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Effect of Derivative Instruments on Other Comprehensive Income (Loss)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock" xlink:to="us-gaap_ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfDerivativeInstrumentsEffectOnOtherComprehensiveIncomeLossTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Derivative Instruments Effect On Other Comprehensive Income Loss Table [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Gains (Losses) on Derivative Instruments not Designated as Hedging Instruments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock" xlink:to="us-gaap_ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfOtherDerivativesNotDesignatedAsHedgingInstrumentsStatementsOfFinancialPerformanceAndFinancialPositionLocationTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Other Derivatives Not Designated As Hedging Instruments Statements Of Financial Performance And Financial Position Location Table [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Fair Value of Assets and Liabilities Measured on Recurring Basis</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock" xlink:to="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfFairValueAssetsAndLiabilitiesMeasuredOnRecurringBasisTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Fair Value Assets And Liabilities Measured On Recurring Basis Table [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByBalanceSheetGroupingTextBlock" xlink:type="locator" xlink:label="us-gaap_FairValueByBalanceSheetGroupingTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueByBalanceSheetGroupingTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Estimated Fair Values of Financial Assets and Liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByBalanceSheetGroupingTextBlock" xlink:to="us-gaap_FairValueByBalanceSheetGroupingTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueByBalanceSheetGroupingTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value By Balance Sheet Grouping [Text Block]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ScheduleOfNoncontrollingInterestTableTextBlock" xlink:type="locator" xlink:label="smhi_ScheduleOfNoncontrollingInterestTableTextBlock" />
    <link:label xml:lang="en-US" xlink:label="smhi_ScheduleOfNoncontrollingInterestTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Tabular disclosure of noncontrolling interest.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ScheduleOfNoncontrollingInterestTableTextBlock" xlink:to="smhi_ScheduleOfNoncontrollingInterestTableTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ScheduleOfNoncontrollingInterestTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Noncontrolling Interests in the Company&apos;s Consolidated Subsidiaries</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ScheduleOfNoncontrollingInterestTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Noncontrolling Interest Table [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Equity Incentive Plan Transactions</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfShareBasedCompensationActivityTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Share Based Compensation Activity Table [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock" xlink:type="locator" xlink:label="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Restricted Stock Transactions</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock" xlink:to="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NonvestedRestrictedStockSharesActivityTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Nonvested Restricted Stock Shares Activity Table [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Stock Option Transactions</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock" xlink:to="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfShareBasedCompensationStockOptionsActivityTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Share Based Compensation Stock Options Activity Table [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentReportingAbstract" xlink:type="locator" xlink:label="us-gaap_SegmentReportingAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentReportingAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting [Abstract]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingAbstract" xlink:to="us-gaap_SegmentReportingAbstract_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Segment Reporting Information, by Segment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Segment Reporting Information By Segment [Text Block]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:type="locator" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Assets Held for Sale</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock" xlink:to="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfDisposalGroupsIncludingDiscontinuedOperationsIncomeStatementBalanceSheetAndAdditionalDisclosuresTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Disposal Groups Including Discontinued Operations Income Statement Balance Sheet And Additional Disclosures [Text Block]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ScheduleIIValuationAndQualifyingAccountsTableTextBlock" xlink:type="locator" xlink:label="smhi_ScheduleIIValuationAndQualifyingAccountsTableTextBlock" />
    <link:label xml:lang="en-US" xlink:label="smhi_ScheduleIIValuationAndQualifyingAccountsTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Tabular disclosure of Schedule II Valuation and Qualifying Accounts.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ScheduleIIValuationAndQualifyingAccountsTableTextBlock" xlink:to="smhi_ScheduleIIValuationAndQualifyingAccountsTableTextBlock_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ScheduleIIValuationAndQualifyingAccountsTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule of Valuation and Qualifying Accounts</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ScheduleIIValuationAndQualifyingAccountsTableTextBlock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule I I Valuation And Qualifying Accounts Table [Text Block]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NatureOfOperationsAndAccountingPoliciesLineItems" xlink:type="locator" xlink:label="smhi_NatureOfOperationsAndAccountingPoliciesLineItems" />
    <link:label xml:lang="en-US" xlink:label="smhi_NatureOfOperationsAndAccountingPoliciesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Nature of operations and accounting policies [Line Items].</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NatureOfOperationsAndAccountingPoliciesLineItems" xlink:to="smhi_NatureOfOperationsAndAccountingPoliciesLineItems_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NatureOfOperationsAndAccountingPoliciesTable" xlink:type="locator" xlink:label="smhi_NatureOfOperationsAndAccountingPoliciesTable" />
    <link:label xml:lang="en-US" xlink:label="smhi_NatureOfOperationsAndAccountingPoliciesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Nature of operations and accounting policies table.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NatureOfOperationsAndAccountingPoliciesTable" xlink:to="smhi_NatureOfOperationsAndAccountingPoliciesTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NatureOfOperationsAndAccountingPoliciesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Nature Of Operations And Accounting Policies [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NatureOfOperationsAndAccountingPoliciesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Nature Of Operations And Accounting Policies [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_StatementGeographicalAxis" xlink:type="locator" xlink:label="srt_StatementGeographicalAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_StatementGeographicalAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographical</link:label>
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    <link:label xml:lang="en-US" xlink:label="srt_StatementGeographicalAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Geographical [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_SegmentGeographicalDomain" xlink:type="locator" xlink:label="srt_SegmentGeographicalDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_SegmentGeographicalDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographical</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_SegmentGeographicalDomain" xlink:to="srt_SegmentGeographicalDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_SegmentGeographicalDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Segment Geographical [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_US" xlink:type="locator" xlink:label="country_US" />
    <link:label xml:lang="en-US" xlink:label="country_US_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">UNITED STATES</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_US" xlink:to="country_US_lbl" />
    <link:label xml:lang="en-US" xlink:label="country_US_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">UNITED STATES</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AfricaAndEuropeMember" xlink:type="locator" xlink:label="smhi_AfricaAndEuropeMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_AfricaAndEuropeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Africa and Europe.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_AfricaAndEuropeMember" xlink:to="smhi_AfricaAndEuropeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_AfricaAndEuropeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Africa and Europe</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AfricaAndEuropeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Africa And Europe [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_MiddleEastAndAsiaMember" xlink:type="locator" xlink:label="smhi_MiddleEastAndAsiaMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_MiddleEastAndAsiaMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to Middle East and Asia.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_MiddleEastAndAsiaMember" xlink:to="smhi_MiddleEastAndAsiaMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_MiddleEastAndAsiaMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Middle East and Asia</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_MiddleEastAndAsiaMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Middle East And Asia [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LatinAmericaMember" xlink:type="locator" xlink:label="srt_LatinAmericaMember" />
    <link:label xml:lang="en-US" xlink:label="srt_LatinAmericaMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Latin America</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_LatinAmericaMember" xlink:to="srt_LatinAmericaMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_LatinAmericaMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Latin America [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_MexMarMember" xlink:type="locator" xlink:label="smhi_MexMarMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_MexMarMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to MexMar.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_MexMarMember" xlink:to="smhi_MexMarMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_MexMarMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">MexMar</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_MexMarMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Mex Mar [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACORMarineInternationalLLCMember" xlink:type="locator" xlink:label="smhi_SEACORMarineInternationalLLCMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineInternationalLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">SEACOR Marine International LLC.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACORMarineInternationalLLCMember" xlink:to="smhi_SEACORMarineInternationalLLCMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineInternationalLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SMI</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineInternationalLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Marine International L L C [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_OwnershipAxis" xlink:type="locator" xlink:label="srt_OwnershipAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_OwnershipAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Ownership</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_OwnershipAxis" xlink:to="srt_OwnershipAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_OwnershipAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Ownership [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_OwnershipDomain" xlink:type="locator" xlink:label="srt_OwnershipDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_OwnershipDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Ownership</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_OwnershipDomain" xlink:to="srt_OwnershipDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_OwnershipDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Ownership [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OVHMember" xlink:type="locator" xlink:label="smhi_OVHMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OVHMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">OVH.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OVHMember" xlink:to="smhi_OVHMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OVHMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">OVH</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OVHMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">O V H [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CMEMember" xlink:type="locator" xlink:label="smhi_CMEMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_CMEMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">CME.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CMEMember" xlink:to="smhi_CMEMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CMEMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">CME</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CMEMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">C M E [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SubsidiariesOfCMEMember" xlink:type="locator" xlink:label="smhi_SubsidiariesOfCMEMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SubsidiariesOfCMEMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Subsidiaries of CME.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SubsidiariesOfCMEMember" xlink:to="smhi_SubsidiariesOfCMEMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SubsidiariesOfCMEMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsidiaries of CME</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SubsidiariesOfCMEMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Subsidiaries Of C M E [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="srt_MinimumMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Minimum</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_LegalEntityAxis" xlink:type="locator" xlink:label="dei_LegalEntityAxis" />
    <link:label xml:lang="en-US" xlink:label="dei_LegalEntityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Legal Entity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_LegalEntityAxis" xlink:to="dei_LegalEntityAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_LegalEntityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Legal Entity [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd#dei_EntityDomain" xlink:type="locator" xlink:label="dei_EntityDomain" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Entity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="dei_EntityDomain" xlink:to="dei_EntityDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="dei_EntityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Entity [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACORMarineForeignHoldingsMember" xlink:type="locator" xlink:label="smhi_SEACORMarineForeignHoldingsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineForeignHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">SEACOR Marine Foreign Holdings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACORMarineForeignHoldingsMember" xlink:to="smhi_SEACORMarineForeignHoldingsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineForeignHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Marine Foreign Holdings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineForeignHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Marine Foreign Holdings [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeographicDistributionAxis" xlink:type="locator" xlink:label="us-gaap_GeographicDistributionAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeographicDistributionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographic Distribution</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeographicDistributionAxis" xlink:to="us-gaap_GeographicDistributionAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeographicDistributionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Geographic Distribution [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeographicDistributionDomain" xlink:type="locator" xlink:label="us-gaap_GeographicDistributionDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeographicDistributionDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographic Distribution</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeographicDistributionDomain" xlink:to="us-gaap_GeographicDistributionDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeographicDistributionDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Geographic Distribution [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeographicDistributionDomesticMember" xlink:type="locator" xlink:label="us-gaap_GeographicDistributionDomesticMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeographicDistributionDomesticMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographic Distribution, Domestic</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeographicDistributionDomesticMember" xlink:to="us-gaap_GeographicDistributionDomesticMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeographicDistributionDomesticMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Geographic Distribution Domestic [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationAxis" xlink:type="locator" xlink:label="us-gaap_BalanceSheetLocationAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Balance Sheet Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationAxis" xlink:to="us-gaap_BalanceSheetLocationAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BalanceSheetLocationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Balance Sheet Location [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BalanceSheetLocationDomain" xlink:type="locator" xlink:label="us-gaap_BalanceSheetLocationDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Balance Sheet Location</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BalanceSheetLocationDomain" xlink:to="us-gaap_BalanceSheetLocationDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BalanceSheetLocationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Balance Sheet Location [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PrepaidCharterModificationAndReservationMember" xlink:type="locator" xlink:label="smhi_PrepaidCharterModificationAndReservationMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PrepaidCharterModificationAndReservationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Prepaid charter modification and reservation.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PrepaidCharterModificationAndReservationMember" xlink:to="smhi_PrepaidCharterModificationAndReservationMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PrepaidCharterModificationAndReservationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid Charter Modification And Reservation</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PrepaidCharterModificationAndReservationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Charter Modification And Reservation [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PrepaidVesselManagementFeesMember" xlink:type="locator" xlink:label="smhi_PrepaidVesselManagementFeesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PrepaidVesselManagementFeesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Prepaid vessel management fees.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PrepaidVesselManagementFeesMember" xlink:to="smhi_PrepaidVesselManagementFeesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PrepaidVesselManagementFeesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Prepaid Vessel Management Fees</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PrepaidVesselManagementFeesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Prepaid Vessel Management Fees [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationTypeAxis" xlink:type="locator" xlink:label="us-gaap_ReclassificationTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ReclassificationTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reclassification, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ReclassificationTypeAxis" xlink:to="us-gaap_ReclassificationTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ReclassificationTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Reclassification Type [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ReclassificationTypeDomain" xlink:type="locator" xlink:label="us-gaap_ReclassificationTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ReclassificationTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reclassification, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ReclassificationTypeDomain" xlink:to="us-gaap_ReclassificationTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ReclassificationTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Reclassification Type [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ContractCompletionsAndCertainReclassificationsMember" xlink:type="locator" xlink:label="smhi_ContractCompletionsAndCertainReclassificationsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ContractCompletionsAndCertainReclassificationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Contract completions and certain reclassifications.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ContractCompletionsAndCertainReclassificationsMember" xlink:to="smhi_ContractCompletionsAndCertainReclassificationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ContractCompletionsAndCertainReclassificationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contract Completions and Certain Reclassifications</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ContractCompletionsAndCertainReclassificationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract Completions And Certain Reclassifications [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentByTypeAxis" xlink:to="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentByTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment By Type [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-Lived Tangible Asset</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTypeDomain" xlink:to="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Type [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OffshoreSupportVesselsMember" xlink:type="locator" xlink:label="smhi_OffshoreSupportVesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Offshore support vessels member.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OffshoreSupportVesselsMember" xlink:to="smhi_OffshoreSupportVesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offshore Support Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Offshore Support Vessels [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementOperatingActivitiesSegmentAxis" xlink:type="locator" xlink:label="us-gaap_StatementOperatingActivitiesSegmentAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementOperatingActivitiesSegmentAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Activities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementOperatingActivitiesSegmentAxis" xlink:to="us-gaap_StatementOperatingActivitiesSegmentAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementOperatingActivitiesSegmentAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Operating Activities Segment [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentOperatingActivitiesDomain" xlink:type="locator" xlink:label="us-gaap_SegmentOperatingActivitiesDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentOperatingActivitiesDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Activities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentOperatingActivitiesDomain" xlink:to="us-gaap_SegmentOperatingActivitiesDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentOperatingActivitiesDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Segment Operating Activities [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentContinuingOperationsMember" xlink:type="locator" xlink:label="us-gaap_SegmentContinuingOperationsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentContinuingOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Continuing Operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentContinuingOperationsMember" xlink:to="us-gaap_SegmentContinuingOperationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentContinuingOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Segment Continuing Operations [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentDiscontinuedOperationsMember" xlink:type="locator" xlink:label="us-gaap_SegmentDiscontinuedOperationsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentDiscontinuedOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discontinued Operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentDiscontinuedOperationsMember" xlink:to="us-gaap_SegmentDiscontinuedOperationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentDiscontinuedOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Segment Discontinued Operations [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EmergencyResponseAndRescueVesselMember" xlink:type="locator" xlink:label="smhi_EmergencyResponseAndRescueVesselMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_EmergencyResponseAndRescueVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Emergency response and rescue vessel member.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EmergencyResponseAndRescueVesselMember" xlink:to="smhi_EmergencyResponseAndRescueVesselMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EmergencyResponseAndRescueVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">ERRVs</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EmergencyResponseAndRescueVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Emergency Response And Rescue Vessel [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LiftboatVesselsMember" xlink:type="locator" xlink:label="smhi_LiftboatVesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_LiftboatVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Liftboat vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LiftboatVesselsMember" xlink:to="smhi_LiftboatVesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_LiftboatVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liftboat Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LiftboatVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liftboat Vessels [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AnchorHandlingTowingSupplyVesselMember" xlink:type="locator" xlink:label="smhi_AnchorHandlingTowingSupplyVesselMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_AnchorHandlingTowingSupplyVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to anchor handling towing supply.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_AnchorHandlingTowingSupplyVesselMember" xlink:to="smhi_AnchorHandlingTowingSupplyVesselMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_AnchorHandlingTowingSupplyVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Anchor Handling Towing Supply</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AnchorHandlingTowingSupplyVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Anchor Handling Towing Supply Vessel [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SpecialtyVesselMember" xlink:type="locator" xlink:label="smhi_SpecialtyVesselMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SpecialtyVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Specialty vessel member.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SpecialtyVesselMember" xlink:to="smhi_SpecialtyVesselMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SpecialtyVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Specialty Vessel</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SpecialtyVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Specialty Vessel [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_VesselUnderConstructionMember" xlink:type="locator" xlink:label="smhi_VesselUnderConstructionMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_VesselUnderConstructionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Vessel under construction.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_VesselUnderConstructionMember" xlink:to="smhi_VesselUnderConstructionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_VesselUnderConstructionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vessel Under Construction</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_VesselUnderConstructionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vessel Under Construction [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:type="locator" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Securities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis" xlink:to="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AntidilutiveSecuritiesExcludedFromComputationOfEarningsPerShareByAntidilutiveSecuritiesAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Excluded From Computation Of Earnings Per Share By Antidilutive Securities [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AntidilutiveSecuritiesNameDomain" xlink:type="locator" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Antidilutive Securities, Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AntidilutiveSecuritiesNameDomain" xlink:to="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AntidilutiveSecuritiesNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Antidilutive Securities Name [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedStockMember" xlink:type="locator" xlink:label="us-gaap_RestrictedStockMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedStockMember" xlink:to="us-gaap_RestrictedStockMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Stock [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmployeeStockOptionMember" xlink:type="locator" xlink:label="us-gaap_EmployeeStockOptionMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeStockOptionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Stock Option</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmployeeStockOptionMember" xlink:to="us-gaap_EmployeeStockOptionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmployeeStockOptionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Employee Stock Option [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AwardTypeAxis" xlink:type="locator" xlink:label="us-gaap_AwardTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AwardTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Award Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AwardTypeAxis" xlink:to="us-gaap_AwardTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AwardTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Award Type [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Award Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardAwardTypeAndPlanNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangements By Share Based Payment Award Award Type And Plan Name [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PerformanceSharesMember" xlink:type="locator" xlink:label="us-gaap_PerformanceSharesMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PerformanceSharesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Performance Share Awards</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PerformanceSharesMember" xlink:to="us-gaap_PerformanceSharesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PerformanceSharesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Performance Shares [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:type="locator" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounting Standards Update</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis" xlink:to="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AdjustmentsForNewAccountingPronouncementsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments For New Accounting Pronouncements [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TypeOfAdoptionMember" xlink:type="locator" xlink:label="us-gaap_TypeOfAdoptionMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TypeOfAdoptionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounting Standards Update</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfAdoptionMember" xlink:to="us-gaap_TypeOfAdoptionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TypeOfAdoptionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Type Of Adoption [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccountingStandardsUpdate201602Member" xlink:type="locator" xlink:label="us-gaap_AccountingStandardsUpdate201602Member" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccountingStandardsUpdate201602Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accounting Standards Update 2016-02</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccountingStandardsUpdate201602Member" xlink:to="us-gaap_AccountingStandardsUpdate201602Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccountingStandardsUpdate201602Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accounting Standards Update201602 [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:type="locator" xlink:label="srt_CumulativeEffectPeriodOfAdoptionAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_CumulativeEffectPeriodOfAdoptionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cumulative Effect, Period of Adoption</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_CumulativeEffectPeriodOfAdoptionAxis" xlink:to="srt_CumulativeEffectPeriodOfAdoptionAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_CumulativeEffectPeriodOfAdoptionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cumulative Effect Period Of Adoption [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:type="locator" xlink:label="srt_CumulativeEffectPeriodOfAdoptionDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_CumulativeEffectPeriodOfAdoptionDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cumulative Effect, Period of Adoption</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_CumulativeEffectPeriodOfAdoptionDomain" xlink:to="srt_CumulativeEffectPeriodOfAdoptionDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_CumulativeEffectPeriodOfAdoptionDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cumulative Effect Period Of Adoption [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:type="locator" xlink:label="srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" />
    <link:label xml:lang="en-US" xlink:label="srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cumulative Effect, Period of Adoption, Adjustment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember" xlink:to="srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_CumulativeEffectPeriodOfAdoptionAdjustmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cumulative Effect Period Of Adoption Adjustment [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:type="locator" xlink:label="us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in Accounting Principle, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis" xlink:to="us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AdjustmentsForChangeInAccountingPrincipleAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Adjustments For Change In Accounting Principle [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ChangeInAccountingPrincipleMember" xlink:type="locator" xlink:label="us-gaap_ChangeInAccountingPrincipleMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ChangeInAccountingPrincipleMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in Accounting Principle, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ChangeInAccountingPrincipleMember" xlink:to="us-gaap_ChangeInAccountingPrincipleMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ChangeInAccountingPrincipleMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Change In Accounting Principle [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ChangeInAccountingPrincipleForEquipmentOfficeAndLandLeasesMember" xlink:type="locator" xlink:label="smhi_ChangeInAccountingPrincipleForEquipmentOfficeAndLandLeasesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ChangeInAccountingPrincipleForEquipmentOfficeAndLandLeasesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to the change in accounting principle for equipment, office and land leases.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ChangeInAccountingPrincipleForEquipmentOfficeAndLandLeasesMember" xlink:to="smhi_ChangeInAccountingPrincipleForEquipmentOfficeAndLandLeasesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ChangeInAccountingPrincipleForEquipmentOfficeAndLandLeasesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in Accounting Principle for Equipment, Office and Land Leases</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ChangeInAccountingPrincipleForEquipmentOfficeAndLandLeasesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Change In Accounting Principle For Equipment Office And Land Leases [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ChangeInAccountingPrincipleForUnamortizedDeferredGainsMember" xlink:type="locator" xlink:label="smhi_ChangeInAccountingPrincipleForUnamortizedDeferredGainsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ChangeInAccountingPrincipleForUnamortizedDeferredGainsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to the change in accounting principle for unamortized deferred gains.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ChangeInAccountingPrincipleForUnamortizedDeferredGainsMember" xlink:to="smhi_ChangeInAccountingPrincipleForUnamortizedDeferredGainsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ChangeInAccountingPrincipleForUnamortizedDeferredGainsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Change in Accounting Principle for Unamortized Deferred Gains</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ChangeInAccountingPrincipleForUnamortizedDeferredGainsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Change In Accounting Principle For Unamortized Deferred Gains [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NatureOfOperationsAndAccountingPoliciesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Nature Of Operations And Accounting Policies [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NatureOfOperationsAndAccountingPoliciesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Nature Of Operations And Accounting Policies [Line Items]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NumberOfReportableSegments" xlink:type="locator" xlink:label="us-gaap_NumberOfReportableSegments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of reportable segments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NumberOfReportableSegments" xlink:to="us-gaap_NumberOfReportableSegments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NumberOfReportableSegments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Reportable Segments</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVessels" xlink:type="locator" xlink:label="smhi_NumberOfVessels" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVessels" xlink:to="smhi_NumberOfVessels_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVesselsOwned" xlink:type="locator" xlink:label="smhi_NumberOfVesselsOwned" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of vessels owned.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVesselsOwned" xlink:to="smhi_NumberOfVesselsOwned_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVesselsLeasedIn" xlink:type="locator" xlink:label="smhi_NumberOfVesselsLeasedIn" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsLeasedIn_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of vessels leased in.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVesselsLeasedIn" xlink:to="smhi_NumberOfVesselsLeasedIn_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVesselsManagedIn" xlink:type="locator" xlink:label="smhi_NumberOfVesselsManagedIn" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsManagedIn_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of vessels managed-in.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVesselsManagedIn" xlink:to="smhi_NumberOfVesselsManagedIn_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels owned</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessels Owned</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsLeasedIn_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels leased-in</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsLeasedIn_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessels Leased In</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsManagedIn_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels managed-in</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsManagedIn_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessels Managed In</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVesselsJointVentured" xlink:type="locator" xlink:label="smhi_NumberOfVesselsJointVentured" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsJointVentured_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of vessels joint ventured.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVesselsJointVentured" xlink:to="smhi_NumberOfVesselsJointVentured_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsJointVentured_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels joint ventured</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsJointVentured_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessels Joint Ventured</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity method investment, ownership percentage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentOwnershipPercentage" xlink:to="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Ownership Percentage</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" xlink:type="locator" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Noncontrolling interest, ownership percentage by noncontrolling owners</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners" xlink:to="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Minority Interest Ownership Percentage By Noncontrolling Owners</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerLiability" xlink:type="locator" xlink:label="us-gaap_ContractWithCustomerLiability" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Balance at beginning of year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiability" xlink:to="us-gaap_ContractWithCustomerLiability_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Liability</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredRevenueAdditions" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueAdditions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueAdditions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenues deferred during the year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueAdditions" xlink:to="us-gaap_DeferredRevenueAdditions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueAdditions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Additions</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredRevenueRevenueRecognized1" xlink:type="locator" xlink:label="us-gaap_DeferredRevenueRevenueRecognized1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueRevenueRecognized1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Revenues recognized and reclassifications during the year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredRevenueRevenueRecognized1" xlink:to="us-gaap_DeferredRevenueRevenueRecognized1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredRevenueRevenueRecognized1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Revenue Revenue Recognized1</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Balance at end of year</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Contract with customer, liability</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:type="locator" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Contract with customer, liability, revenue recognized</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ContractWithCustomerLiabilityRevenueRecognized" xlink:to="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ContractWithCustomerLiabilityRevenueRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Contract With Customer Liability Revenue Recognized</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Cash" xlink:type="locator" xlink:label="us-gaap_Cash" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Cash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Cash" xlink:to="us-gaap_Cash_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Cash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RestrictedCash" xlink:type="locator" xlink:label="us-gaap_RestrictedCash" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Restricted cash</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RestrictedCash" xlink:to="us-gaap_RestrictedCash_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestrictedCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Restricted Cash</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:type="locator" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents" xlink:to="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalents_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash Cash Equivalents Restricted Cash And Restricted Cash Equivalents</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InventoryValuationReserves" xlink:type="locator" xlink:label="us-gaap_InventoryValuationReserves" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InventoryValuationReserves_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Inventory reserves</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InventoryValuationReserves" xlink:to="us-gaap_InventoryValuationReserves_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InventoryValuationReserves_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Inventory Valuation Reserves</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated useful life (Year)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentUsefulLife" xlink:to="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentUsefulLife_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Useful Life</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OffshoreSupportVesselsAnchorHandlingTowingSupplyMember" xlink:type="locator" xlink:label="smhi_OffshoreSupportVesselsAnchorHandlingTowingSupplyMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsAnchorHandlingTowingSupplyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information pertaining to anchor handling towing supply included within offshore support vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OffshoreSupportVesselsAnchorHandlingTowingSupplyMember" xlink:to="smhi_OffshoreSupportVesselsAnchorHandlingTowingSupplyMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsAnchorHandlingTowingSupplyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offshore Support Vessels, Anchor Handling Towing Supply</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsAnchorHandlingTowingSupplyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Offshore Support Vessels Anchor Handling Towing Supply [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_FastSupportVesselsMember" xlink:type="locator" xlink:label="smhi_FastSupportVesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_FastSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Fast support vessels member.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_FastSupportVesselsMember" xlink:to="smhi_FastSupportVesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_FastSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fast Support Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FastSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fast Support Vessels [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OffshoreSupportVesselsSupplyMember" xlink:type="locator" xlink:label="smhi_OffshoreSupportVesselsSupplyMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsSupplyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information pertaining to supply vessels included within offshore support vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OffshoreSupportVesselsSupplyMember" xlink:to="smhi_OffshoreSupportVesselsSupplyMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsSupplyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offshore Support Vessels, Supply</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsSupplyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Offshore Support Vessels Supply [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OffshoreSupportVesselsSpecialtyMember" xlink:type="locator" xlink:label="smhi_OffshoreSupportVesselsSpecialtyMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsSpecialtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information pertaining to specialty vessels included within offshore support vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OffshoreSupportVesselsSpecialtyMember" xlink:to="smhi_OffshoreSupportVesselsSpecialtyMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsSpecialtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offshore Support Vessels, Specialty</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsSpecialtyMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Offshore Support Vessels Specialty [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OffshoreSupportVesselsLiftboatsMember" xlink:type="locator" xlink:label="smhi_OffshoreSupportVesselsLiftboatsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsLiftboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information pertaining to liftboats included within offshore support vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OffshoreSupportVesselsLiftboatsMember" xlink:to="smhi_OffshoreSupportVesselsLiftboatsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsLiftboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offshore Support Vessels, Liftboats</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreSupportVesselsLiftboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Offshore Support Vessels Liftboats [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_GeneralMachineryAndSparesMember" xlink:type="locator" xlink:label="smhi_GeneralMachineryAndSparesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_GeneralMachineryAndSparesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information pertaining to general machinery and spares.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_GeneralMachineryAndSparesMember" xlink:to="smhi_GeneralMachineryAndSparesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_GeneralMachineryAndSparesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">General Machinery and Spares</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_GeneralMachineryAndSparesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">General Machinery And Spares [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentOtherTypesMember" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherTypesMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherTypesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property, Plant and Equipment, Other Types</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentOtherTypesMember" xlink:to="us-gaap_PropertyPlantAndEquipmentOtherTypesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentOtherTypesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Other Types [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CrewTransferVesselsMember" xlink:type="locator" xlink:label="smhi_CrewTransferVesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_CrewTransferVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to crew transfer vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CrewTransferVesselsMember" xlink:to="smhi_CrewTransferVesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CrewTransferVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Crew Transfer Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CrewTransferVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Crew Transfer Vessels [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net book value</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CarryingValueOfAssetsHeldForSale" xlink:type="locator" xlink:label="smhi_CarryingValueOfAssetsHeldForSale" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarryingValueOfAssetsHeldForSale_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Carrying value of assets held for sale.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CarryingValueOfAssetsHeldForSale" xlink:to="smhi_CarryingValueOfAssetsHeldForSale_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NetProceedsFromSaleOfAssets" xlink:type="locator" xlink:label="smhi_NetProceedsFromSaleOfAssets" />
    <link:label xml:lang="en-US" xlink:label="smhi_NetProceedsFromSaleOfAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Net proceeds from sale of assets.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NetProceedsFromSaleOfAssets" xlink:to="smhi_NetProceedsFromSaleOfAssets_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TransactionCosts" xlink:type="locator" xlink:label="smhi_TransactionCosts" />
    <link:label xml:lang="en-US" xlink:label="smhi_TransactionCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Transaction costs.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TransactionCosts" xlink:to="smhi_TransactionCosts_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BuildingMember" xlink:type="locator" xlink:label="us-gaap_BuildingMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BuildingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Building</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BuildingMember" xlink:to="us-gaap_BuildingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BuildingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Building [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CarryingValueOfAssetsHeldForSale_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Carrying value of assets held for sale</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CarryingValueOfAssetsHeldForSale_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Carrying Value Of Assets Held For Sale</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NetProceedsFromSaleOfAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net proceeds from sale of assets</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NetProceedsFromSaleOfAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Net Proceeds From Sale Of Assets</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainsLossesOnSalesOfAssets" xlink:type="locator" xlink:label="us-gaap_GainsLossesOnSalesOfAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainsLossesOnSalesOfAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain on sale of assets held for sale</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainsLossesOnSalesOfAssets" xlink:to="us-gaap_GainsLossesOnSalesOfAssets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainsLossesOnSalesOfAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Gains Losses On Sales Of Assets</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TransactionCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transaction costs</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TransactionCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Transaction Costs</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Depreciation" xlink:type="locator" xlink:label="us-gaap_Depreciation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Depreciation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Depreciation" xlink:to="us-gaap_Depreciation_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Depreciation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Depreciation</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PropertyPlantAndEquipmentExcludingConstructionInProgress_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net book value</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestCostsIncurredCapitalized" xlink:type="locator" xlink:label="us-gaap_InterestCostsIncurredCapitalized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestCostsIncurredCapitalized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Capitalized interest costs, including allowance for funds used during construction, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestCostsIncurredCapitalized" xlink:to="us-gaap_InterestCostsIncurredCapitalized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestCostsIncurredCapitalized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Costs Incurred Capitalized</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PartialImpairmentOfRightToUseAssets" xlink:type="locator" xlink:label="smhi_PartialImpairmentOfRightToUseAssets" />
    <link:label xml:lang="en-US" xlink:label="smhi_PartialImpairmentOfRightToUseAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Partial impairment of right to use assets.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PartialImpairmentOfRightToUseAssets" xlink:to="smhi_PartialImpairmentOfRightToUseAssets_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AdditionalImpairmentOfRightToUseAssets" xlink:type="locator" xlink:label="smhi_AdditionalImpairmentOfRightToUseAssets" />
    <link:label xml:lang="en-US" xlink:label="smhi_AdditionalImpairmentOfRightToUseAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Additional impairment of right-to-use assets.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_AdditionalImpairmentOfRightToUseAssets" xlink:to="smhi_AdditionalImpairmentOfRightToUseAssets_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:type="locator" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Impairment of long-lived assets held-for-use</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse" xlink:to="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ImpairmentOfLongLivedAssetsHeldForUse_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Impairment Of Long Lived Assets Held For Use</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PartialImpairmentOfRightToUseAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Partial impairment of right to use assets</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PartialImpairmentOfRightToUseAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Partial Impairment Of Right To Use Assets</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AdditionalImpairmentOfRightToUseAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional impairment of right-to-use assets</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AdditionalImpairmentOfRightToUseAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Additional Impairment Of Right To Use Assets</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity method investment, other than temporary impairment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment" xlink:to="us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOtherThanTemporaryImpairment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Other Than Temporary Impairment</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ReclassOfGainToRetainedEarnings" xlink:type="locator" xlink:label="smhi_ReclassOfGainToRetainedEarnings" />
    <link:label xml:lang="en-US" xlink:label="smhi_ReclassOfGainToRetainedEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Reclass of gain to retained earnings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ReclassOfGainToRetainedEarnings" xlink:to="smhi_ReclassOfGainToRetainedEarnings_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ReclassOfGainToRetainedEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred gain activity reclassed to retained earnings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ReclassOfGainToRetainedEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Reclass Of Gain To Retained Earnings</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DeferredGainOnSaleOfPropertyOtherAdjustments" xlink:type="locator" xlink:label="smhi_DeferredGainOnSaleOfPropertyOtherAdjustments" />
    <link:label xml:lang="en-US" xlink:label="smhi_DeferredGainOnSaleOfPropertyOtherAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The amount of other adjustment to deferred gain on sale of property.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DeferredGainOnSaleOfPropertyOtherAdjustments" xlink:to="smhi_DeferredGainOnSaleOfPropertyOtherAdjustments_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_DeferredGainOnSaleOfPropertyOtherAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred gain on sale of property other adjustments</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DeferredGainOnSaleOfPropertyOtherAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Gain On Sale Of Property Other Adjustments</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredGainOnSaleOfProperty" xlink:type="locator" xlink:label="us-gaap_DeferredGainOnSaleOfProperty" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredGainOnSaleOfProperty_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred gain net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredGainOnSaleOfProperty" xlink:to="us-gaap_DeferredGainOnSaleOfProperty_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredGainOnSaleOfProperty_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Gain On Sale Of Property</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:type="locator" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Other Comprehensive Income Loss [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable" xlink:to="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeLossTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Other Comprehensive Income Loss [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedTranslationAdjustmentMember" xlink:type="locator" xlink:label="us-gaap_AccumulatedTranslationAdjustmentMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedTranslationAdjustmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Foreign Currency Adjustment Attributable to Parent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedTranslationAdjustmentMember" xlink:to="us-gaap_AccumulatedTranslationAdjustmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedTranslationAdjustmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Translation Adjustment [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember" xlink:type="locator" xlink:label="us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Gain (Loss), Net, Cash Flow Hedge, Parent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember" xlink:to="us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedGainLossNetCashFlowHedgeParentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Gain Loss Net Cash Flow Hedge Parent [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedOtherComprehensiveIncomeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">AOCI Attributable to Parent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember" xlink:type="locator" xlink:label="us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Foreign Currency Adjustment Attributable to Noncontrolling Interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember" xlink:to="us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedForeignCurrencyAdjustmentAttributableToNoncontrollingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Foreign Currency Adjustment Attributable To Noncontrolling Interest [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember" xlink:type="locator" xlink:label="us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Accumulated Loss, Net, Cash Flow Hedge, Noncontrolling Interest</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember" xlink:to="us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AccumulatedGainLossNetCashFlowHedgeNoncontrollingInterestMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Accumulated Gain Loss Net Cash Flow Hedge Noncontrolling Interest [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AociAttributableToNoncontrollingInterestMember" xlink:type="locator" xlink:label="us-gaap_AociAttributableToNoncontrollingInterestMember" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AociAttributableToNoncontrollingInterestMember" xlink:to="us-gaap_AociAttributableToNoncontrollingInterestMember_lbl" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiability" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiability" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherRestructuringCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Restructuring Costs</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AfricaAndEuropeContinuingOperationsMember" xlink:type="locator" xlink:label="smhi_AfricaAndEuropeContinuingOperationsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_AfricaAndEuropeContinuingOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Africa And Europe continuing operations.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_AfricaAndEuropeContinuingOperationsMember" xlink:to="smhi_AfricaAndEuropeContinuingOperationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_AfricaAndEuropeContinuingOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Africa and Europe, Continuing Operations</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AfricaAndEuropeContinuingOperationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Africa And Europe Continuing Operations [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SeveranceCosts1" xlink:type="locator" xlink:label="us-gaap_SeveranceCosts1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SeveranceCosts1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Severance Charges</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SeveranceCosts1" xlink:to="us-gaap_SeveranceCosts1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SeveranceCosts1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Severance Costs1</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherRestructuringCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Charges</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_RestructuringCharges_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total Charges</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NoteToFinancialStatementDetailsTextual" xlink:type="locator" xlink:label="smhi_NoteToFinancialStatementDetailsTextual" />
    <link:label xml:lang="en-US" xlink:label="smhi_NoteToFinancialStatementDetailsTextual_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Note To Financial Statement Details Textual</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NoteToFinancialStatementDetailsTextual" xlink:to="smhi_NoteToFinancialStatementDetailsTextual_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NoteToFinancialStatementDetailsTextual_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Note To Financial Statement Details Textual</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAxis" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Acquisition</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAxis" xlink:to="us-gaap_BusinessAcquisitionAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionAcquireeDomain" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business Acquisition, Acquiree</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionAcquireeDomain" xlink:to="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionAcquireeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Acquiree [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_MergerAgreementMember" xlink:type="locator" xlink:label="smhi_MergerAgreementMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_MergerAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Merger agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_MergerAgreementMember" xlink:to="smhi_MergerAgreementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_MergerAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Merger Agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_MergerAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Merger Agreement [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityInterestIssuedOrIssuableByTypeAxis" xlink:type="locator" xlink:label="us-gaap_EquityInterestIssuedOrIssuableByTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Interest Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityInterestIssuedOrIssuableByTypeAxis" xlink:to="us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityInterestIssuedOrIssuableByTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Interest Issued Or Issuable By Type [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityInterestIssuedOrIssuableTypeDomain" xlink:type="locator" xlink:label="us-gaap_EquityInterestIssuedOrIssuableTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityInterestIssuedOrIssuableTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Interest Issued or Issuable, Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityInterestIssuedOrIssuableTypeDomain" xlink:to="us-gaap_EquityInterestIssuedOrIssuableTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityInterestIssuedOrIssuableTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Interest Issued Or Issuable Type [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TypeOfArrangementAxis" xlink:type="locator" xlink:label="us-gaap_TypeOfArrangementAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collaborative Arrangement and Arrangement Other than Collaborative</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TypeOfArrangementAxis" xlink:to="us-gaap_TypeOfArrangementAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TypeOfArrangementAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Type Of Arrangement [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:type="locator" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Collaborative Arrangement and Arrangement Other than Collaborative</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ArrangementsAndNonarrangementTransactionsMember" xlink:to="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ArrangementsAndNonarrangementTransactionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Arrangements And Nonarrangement Transactions [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_MergerConsiderationMember" xlink:type="locator" xlink:label="smhi_MergerConsiderationMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_MergerConsiderationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Merger consideration.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_MergerConsiderationMember" xlink:to="smhi_MergerConsiderationMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_MergerConsiderationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Merger Consideration</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_MergerConsiderationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Merger Consideration [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PartnerTypeOfPartnersCapitalAccountAxis" xlink:type="locator" xlink:label="us-gaap_PartnerTypeOfPartnersCapitalAccountAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PartnerTypeOfPartnersCapitalAccountAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Partner Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnerTypeOfPartnersCapitalAccountAxis" xlink:to="us-gaap_PartnerTypeOfPartnersCapitalAccountAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PartnerTypeOfPartnersCapitalAccountAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Partner Type Of Partners Capital Account [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain" xlink:type="locator" xlink:label="us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Partner Type of Partners&apos; Capital Account, Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain" xlink:to="us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PartnerTypeOfPartnersCapitalAccountNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Partner Type Of Partners Capital Account Name [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LimitedPartnerMember" xlink:type="locator" xlink:label="us-gaap_LimitedPartnerMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LimitedPartnerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Limited Partner</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LimitedPartnerMember" xlink:to="us-gaap_LimitedPartnerMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LimitedPartnerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Limited Partner [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PaymentInKindPIKLoanMember" xlink:type="locator" xlink:label="smhi_PaymentInKindPIKLoanMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentInKindPIKLoanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Payment in kind (PIK) loan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PaymentInKindPIKLoanMember" xlink:to="smhi_PaymentInKindPIKLoanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentInKindPIKLoanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">PIK Loan Consideration</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentInKindPIKLoanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Payment In Kind P I K Loan [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PlatformSupplyVesselsMember" xlink:type="locator" xlink:label="smhi_PlatformSupplyVesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PlatformSupplyVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Member stands for platform supply vessels ("PSVs").</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PlatformSupplyVesselsMember" xlink:to="smhi_PlatformSupplyVesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PlatformSupplyVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Platform Supply Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PlatformSupplyVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Platform Supply Vessels [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACOROffshoreDeltaLLCMember" xlink:type="locator" xlink:label="smhi_SEACOROffshoreDeltaLLCMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreDeltaLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">SEACOR Offshore Delta LLC.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACOROffshoreDeltaLLCMember" xlink:to="smhi_SEACOROffshoreDeltaLLCMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreDeltaLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Offshore Delta LLC</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreDeltaLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Offshore Delta L L C [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACOROffshoreAsiaMember" xlink:type="locator" xlink:label="smhi_SEACOROffshoreAsiaMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreAsiaMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">SEACOR offshore asia.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACOROffshoreAsiaMember" xlink:to="smhi_SEACOROffshoreAsiaMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreAsiaMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Offshore Asia</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreAsiaMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Offshore Asia [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SaleAndPurchaseAgreementMember" xlink:type="locator" xlink:label="smhi_SaleAndPurchaseAgreementMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SaleAndPurchaseAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Sale and purchase agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SaleAndPurchaseAgreementMember" xlink:to="smhi_SaleAndPurchaseAgreementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SaleAndPurchaseAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale And Purchase Agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SaleAndPurchaseAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sale And Purchase Agreement [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DeferredPurchaseAgreementsMember" xlink:type="locator" xlink:label="smhi_DeferredPurchaseAgreementsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_DeferredPurchaseAgreementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deferred purchase agreements.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DeferredPurchaseAgreementsMember" xlink:to="smhi_DeferredPurchaseAgreementsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_DeferredPurchaseAgreementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred Purchase Agreements</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DeferredPurchaseAgreementsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Purchase Agreements [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common stock issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued" xlink:to="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionEquityInterestsIssuedOrIssuableNumberOfSharesIssued_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Equity Interests Issued Or Issuable Number Of Shares Issued</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_BusinessCombinationAssumedAndGuaranteeAmount" xlink:type="locator" xlink:label="smhi_BusinessCombinationAssumedAndGuaranteeAmount" />
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationAssumedAndGuaranteeAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination, assumed and guarantee amount.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_BusinessCombinationAssumedAndGuaranteeAmount" xlink:to="smhi_BusinessCombinationAssumedAndGuaranteeAmount_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DebtInstrumentQuarterlyPrincipalPayments" xlink:type="locator" xlink:label="smhi_DebtInstrumentQuarterlyPrincipalPayments" />
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentQuarterlyPrincipalPayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt instrument quarterly principal payments.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DebtInstrumentQuarterlyPrincipalPayments" xlink:to="smhi_DebtInstrumentQuarterlyPrincipalPayments_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfInterestAccruesUnderCreditFacilityPlusMandatoryCost" xlink:type="locator" xlink:label="smhi_PercentageOfInterestAccruesUnderCreditFacilityPlusMandatoryCost" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfInterestAccruesUnderCreditFacilityPlusMandatoryCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of interest accrues under credit facility plus mandatory cost.</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentQuarterlyPrincipalPayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Quarterly principal payments</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfInterestAccruesUnderCreditFacilityPlusMandatoryCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of interest accrues under credit facility plus mandatory cost</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfInterestAccruesUnderCreditFacilityPlusMandatoryCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Interest Accrues Under Credit Facility Plus Mandatory Cost</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentMaturityDate" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentMaturityDate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, maturity date</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentMaturityDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Maturity Date</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AverageAgeOfVessels" xlink:type="locator" xlink:label="smhi_AverageAgeOfVessels" />
    <link:label xml:lang="en-US" xlink:label="smhi_AverageAgeOfVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Average age of vessels.</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" xlink:type="locator" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Percentage Of Voting Interests Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AverageAgeOfVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Average age of vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AverageAgeOfVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Average Age Of Vessels</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetCostBasisForPurchase" xlink:type="locator" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetCostBasisForPurchase" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfInvestmentsTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsTable" />
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    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfInvestmentsTable" xlink:to="us-gaap_ScheduleOfInvestmentsTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfInvestmentsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Investments [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfInvestmentsLineItems" xlink:type="locator" xlink:label="us-gaap_ScheduleOfInvestmentsLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfInvestmentsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Investments [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfInvestmentsLineItems" xlink:to="us-gaap_ScheduleOfInvestmentsLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfInvestmentsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Investments [Line Items]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current Assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Current Assets</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fixed Assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Assets</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Current Liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedCurrentLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Current Liabilities</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Long-Term Liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNoncurrentLiabilitiesLongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Noncurrent Liabilities Long Term Debt</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBookValueOfDebtAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Book Value of Debt Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedBookValueOfDebtAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Book Value Of Debt Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDiscountOfDebtAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discount on Debt Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedDiscountOfDebtAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Discount Of Debt Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedFairValueOfDebtAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel">Fair Value of Debt Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedFairValueOfDebtAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Fair Value Of Debt Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetCostBasisForPurchase_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total Cost Basis for Purchase</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetCostBasisForPurchase_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Net Cost Basis For Purchase</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPurchasePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Purchase Price</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedPurchasePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Purchase Price</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAcquisitionCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Acquisition costs</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedAcquisitionCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Acquisition Costs</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestments" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Equity Investment</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investments</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedNetCostBasisForPurchase_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTotalLabel">Total Cost Basis for Purchase</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PurchasePricePayableForEquityMethodInvestment" xlink:type="locator" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestment" />
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase price payable for equity method investment.</link:label>
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_BusinessCombinationPurchasePricePayableToSellersAtClosingOfTransaction" xlink:type="locator" xlink:label="smhi_BusinessCombinationPurchasePricePayableToSellersAtClosingOfTransaction" />
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationPurchasePricePayableToSellersAtClosingOfTransaction_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination, purchase price payable to sellers at closing of transaction.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_BusinessCombinationPurchasePricePayableToSellersAtClosingOfTransaction" xlink:to="smhi_BusinessCombinationPurchasePricePayableToSellersAtClosingOfTransaction_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearOne" xlink:type="locator" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearOne" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearThree" xlink:type="locator" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearThree" />
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business acquisition percentage of purchase price fixed accrued interest rate for membership interest in year three.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearThree" xlink:to="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearThree_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearFour" xlink:type="locator" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearFour" />
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business acquisition percentage of purchase price fixed accrued interest rate for membership interest in year four.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearFour" xlink:to="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearFour_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price payable for membership interest</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Purchase Price Payable For Equity Method Investment</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationPurchasePricePayableToSellersAtClosingOfTransaction_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price payable to sellers at closing of transaction</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationPurchasePricePayableToSellersAtClosingOfTransaction_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Purchase Price Payable To Sellers At Closing Of Transaction</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price for membership interests annual installment payment in first year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Purchase Price For Membership Interests Annual Installment Payment In Year One</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price for membership interests annual installment payment in second year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Purchase Price For Membership Interests Annual Installment Payment In Year Two</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price for membership interests annual installment payment in third year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Purchase Price For Membership Interests Annual Installment Payment In Year Three</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price for membership interests annual installment payment in fourth year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceForMembershipInterestsAnnualInstallmentPaymentInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Purchase Price For Membership Interests Annual Installment Payment In Year Four</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price fixed accrued interest rate in first year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Percentage Of Purchase Price Fixed Accrued Interest Rate For Membership Interest In Year One</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price fixed accrued interest rate in second year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Percentage Of Purchase Price Fixed Accrued Interest Rate For Membership Interest In Year Two</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price fixed accrued interest rate in third year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Percentage Of Purchase Price Fixed Accrued Interest Rate For Membership Interest In Year Three</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price fixed accrued interest rate in fourth year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPercentageOfPurchasePriceFixedAccruedInterestRateForMembershipInterestInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Percentage Of Purchase Price Fixed Accrued Interest Rate For Membership Interest In Year Four</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_BusinessAcquisitionPurchasePriceAmortizationPeriod" xlink:type="locator" xlink:label="smhi_BusinessAcquisitionPurchasePriceAmortizationPeriod" />
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceAmortizationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business acquisition purchase price amortization period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_BusinessAcquisitionPurchasePriceAmortizationPeriod" xlink:to="smhi_BusinessAcquisitionPurchasePriceAmortizationPeriod_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVesselsDeliveredToCompany" xlink:type="locator" xlink:label="smhi_NumberOfVesselsDeliveredToCompany" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsDeliveredToCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The number of vessels deliverd to the company.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVesselsDeliveredToCompany" xlink:to="smhi_NumberOfVesselsDeliveredToCompany_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business acquisition, aggregate amount outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities" xlink:to="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationRecognizedIdentifiableAssetsAcquiredAndLiabilitiesAssumedLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Recognized Identifiable Assets Acquired And Liabilities Assumed Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceAmortizationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business acquisition, amortization period of purchase price</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessAcquisitionPurchasePriceAmortizationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Acquisition Purchase Price Amortization Period</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentDescriptionOfVariableRateBasis" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, description of floating interest rate basis</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis" xlink:to="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentDescriptionOfVariableRateBasis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Description Of Variable Rate Basis</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, basis spread on floating interest rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1" xlink:to="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentBasisSpreadOnVariableRate1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Basis Spread On Variable Rate1</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsDeliveredToCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels delivered to the company</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsDeliveredToCompany_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessels Delivered To Company</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVesselsOwnedWithHighSpecification" xlink:type="locator" xlink:label="smhi_NumberOfVesselsOwnedWithHighSpecification" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwnedWithHighSpecification_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of vessels owned with high specification</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVesselsOwnedWithHighSpecification" xlink:to="smhi_NumberOfVesselsOwnedWithHighSpecification_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVesselsOwnedWithIdenticalSpecification" xlink:type="locator" xlink:label="smhi_NumberOfVesselsOwnedWithIdenticalSpecification" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwnedWithIdenticalSpecification_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of vessels owned with identical specification.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVesselsOwnedWithIdenticalSpecification" xlink:to="smhi_NumberOfVesselsOwnedWithIdenticalSpecification_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwnedWithHighSpecification_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels owned with high specification</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwnedWithHighSpecification_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessels Owned With High Specification</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwnedWithIdenticalSpecification_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels owned with identical specification</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselsOwnedWithIdenticalSpecification_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessels Owned With Identical Specification</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CapitalExpendituresAndPaymentsOnEquipment" xlink:type="locator" xlink:label="smhi_CapitalExpendituresAndPaymentsOnEquipment" />
    <link:label xml:lang="en-US" xlink:label="smhi_CapitalExpendituresAndPaymentsOnEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Capital expenditures and payments on equipment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CapitalExpendituresAndPaymentsOnEquipment" xlink:to="smhi_CapitalExpendituresAndPaymentsOnEquipment_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Property Plant And Equipment [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable" xlink:to="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfPropertyPlantAndEquipmentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Property Plant And Equipment [Table]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_VesselUnderConstructionAndOtherEquipmentMember" xlink:type="locator" xlink:label="smhi_VesselUnderConstructionAndOtherEquipmentMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_VesselUnderConstructionAndOtherEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Vessel under construction and other equipment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_VesselUnderConstructionAndOtherEquipmentMember" xlink:to="smhi_VesselUnderConstructionAndOtherEquipmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_VesselUnderConstructionAndOtherEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vessel under Construction and Other Equipment</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_VesselUnderConstructionAndOtherEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vessel Under Construction And Other Equipment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AnchorHandlingTowingSupplyVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Anchor Handling Towing Supply</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PlatformSupplyVesselsAndFastSupportVesselsMember" xlink:type="locator" xlink:label="smhi_PlatformSupplyVesselsAndFastSupportVesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PlatformSupplyVesselsAndFastSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Platform supply vessels and fast support vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PlatformSupplyVesselsAndFastSupportVesselsMember" xlink:to="smhi_PlatformSupplyVesselsAndFastSupportVesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PlatformSupplyVesselsAndFastSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Platform Supply Vessels And Fast Support Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PlatformSupplyVesselsAndFastSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Platform Supply Vessels And Fast Support Vessels [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentAxis" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentAxis" xlink:to="us-gaap_DebtInstrumentAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentNameDomain" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument, Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentNameDomain" xlink:to="us-gaap_DebtInstrumentNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Name [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_FalconGlobalUSATermLoanFacilityMember" xlink:type="locator" xlink:label="smhi_FalconGlobalUSATermLoanFacilityMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalUSATermLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to Falcon Global USA LLC term loan facility.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_FalconGlobalUSATermLoanFacilityMember" xlink:to="smhi_FalconGlobalUSATermLoanFacilityMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalUSATermLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Falcon Global U S A Term Loan Facility</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalUSATermLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Falcon Global U S A Term Loan Facility [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_VesselsMember" xlink:type="locator" xlink:label="smhi_VesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_VesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_VesselsMember" xlink:to="smhi_VesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_VesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_VesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vessels [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NorthSeaERRVFleetMember" xlink:type="locator" xlink:label="smhi_NorthSeaERRVFleetMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_NorthSeaERRVFleetMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">North Sea ERRV fleet.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NorthSeaERRVFleetMember" xlink:to="smhi_NorthSeaERRVFleetMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NorthSeaERRVFleetMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">North Sea ERRV Fleet</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NorthSeaERRVFleetMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">North Sea E R R V Fleet [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LiftboatsMember" xlink:type="locator" xlink:label="smhi_LiftboatsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_LiftboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to liftboats.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LiftboatsMember" xlink:to="smhi_LiftboatsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_LiftboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liftboats</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LiftboatsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liftboats [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentLineItems" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property Plant And Equipment [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentLineItems" xlink:to="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CapitalExpendituresAndPaymentsOnEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Capital expenditures and payments on equipment</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CapitalExpendituresAndPaymentsOnEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Capital Expenditures And Payments On Equipment</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfEquipmentAcquired" xlink:type="locator" xlink:label="smhi_NumberOfEquipmentAcquired" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the number of of equipment acquired.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfEquipmentAcquired" xlink:to="smhi_NumberOfEquipmentAcquired_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Equipment Acquired</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfEquipmentHeldForSaleExcludedFromDeliveriesOfOffshoreSupportVessels" xlink:type="locator" xlink:label="smhi_NumberOfEquipmentHeldForSaleExcludedFromDeliveriesOfOffshoreSupportVessels" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentHeldForSaleExcludedFromDeliveriesOfOffshoreSupportVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of equipment held for sale excluded from deliveries of offshore support vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfEquipmentHeldForSaleExcludedFromDeliveriesOfOffshoreSupportVessels" xlink:to="smhi_NumberOfEquipmentHeldForSaleExcludedFromDeliveriesOfOffshoreSupportVessels_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfEquipmentAcquiredExcludedFromDeliveriesOfOffshoreSupportVessels" xlink:type="locator" xlink:label="smhi_NumberOfEquipmentAcquiredExcludedFromDeliveriesOfOffshoreSupportVessels" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentAcquiredExcludedFromDeliveriesOfOffshoreSupportVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of equipment acquired excluded from deliveries of offshore support vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfEquipmentAcquiredExcludedFromDeliveriesOfOffshoreSupportVessels" xlink:to="smhi_NumberOfEquipmentAcquiredExcludedFromDeliveriesOfOffshoreSupportVessels_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentAcquiredExcludedFromDeliveriesOfOffshoreSupportVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of equipment acquired excludes from deliveries of offshore support vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentAcquiredExcludedFromDeliveriesOfOffshoreSupportVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Equipment Acquired Excluded From Deliveries Of Offshore Support Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentHeldForSaleExcludedFromDeliveriesOfOffshoreSupportVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of equipment held for sale excluded from deliveries of offshore support vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentHeldForSaleExcludedFromDeliveriesOfOffshoreSupportVessels_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Equipment Held For Sale Excluded From Deliveries Of Offshore Support Vessels</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfAdditionalJointVenturesHeldInterests" xlink:type="locator" xlink:label="smhi_NumberOfAdditionalJointVenturesHeldInterests" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfAdditionalJointVenturesHeldInterests_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of additional joint ventures held interests.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfAdditionalJointVenturesHeldInterests" xlink:to="smhi_NumberOfAdditionalJointVenturesHeldInterests_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" xlink:type="locator" xlink:label="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of equity percentage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction" xlink:to="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SaleOfStockPercentageOfOwnershipAfterTransaction_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sale Of Stock Percentage Of Ownership After Transaction</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentAggregateCost" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentAggregateCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentAggregateCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Aggregate purchase price</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentAggregateCost" xlink:to="us-gaap_EquityMethodInvestmentAggregateCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentAggregateCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Aggregate Cost</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt outstanding under revolving credit facility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod" xlink:to="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityMaximumAmountOutstandingDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Maximum Amount Outstanding During Period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfAdditionalJointVenturesHeldInterests_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of additional joint ventures held interests</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfAdditionalJointVenturesHeldInterests_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Additional Joint Ventures Held Interests</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain (loss) on disposition of property, plant and equipment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfPropertyPlantEquipment" xlink:to="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Gain Loss On Sale Of Property Plant Equipment</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentGross" xlink:type="locator" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentGross" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from sale of property plant and equipment gross.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentGross" xlink:to="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentGross_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PaymentsForTransactionsFeesAndOtherCosts" xlink:type="locator" xlink:label="smhi_PaymentsForTransactionsFeesAndOtherCosts" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForTransactionsFeesAndOtherCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Payments for transactions fees and other costs.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PaymentsForTransactionsFeesAndOtherCosts" xlink:to="smhi_PaymentsForTransactionsFeesAndOtherCosts_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CashSoldOnPropertyPlantAndEquipmentDisposal" xlink:type="locator" xlink:label="smhi_CashSoldOnPropertyPlantAndEquipmentDisposal" />
    <link:label xml:lang="en-US" xlink:label="smhi_CashSoldOnPropertyPlantAndEquipmentDisposal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash sold on property plant and equipment disposal.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CashSoldOnPropertyPlantAndEquipmentDisposal" xlink:to="smhi_CashSoldOnPropertyPlantAndEquipmentDisposal_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveLabel">Total Proceeds Received</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Sale Of Property Plant And Equipment Gross</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForTransactionsFeesAndOtherCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transactions Fees and other Costs</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForTransactionsFeesAndOtherCosts_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Payments For Transactions Fees And Other Costs</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CashSoldOnPropertyPlantAndEquipmentDisposal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Sold</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CashSoldOnPropertyPlantAndEquipmentDisposal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash Sold On Property Plant And Equipment Disposal</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total Net Proceeds</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentDisposals" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentDisposals" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentDisposals_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: Net Equity in Windcat Workboats, net of cash sold</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentDisposals" xlink:to="us-gaap_PropertyPlantAndEquipmentDisposals_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentDisposals_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Disposals</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PropertyPlantAndEquipmentTransfersAndChanges" xlink:type="locator" xlink:label="us-gaap_PropertyPlantAndEquipmentTransfersAndChanges" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentTransfersAndChanges_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Less: January Income on Discontinued Operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PropertyPlantAndEquipmentTransfersAndChanges" xlink:to="us-gaap_PropertyPlantAndEquipmentTransfersAndChanges_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentTransfersAndChanges_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant And Equipment Transfers And Changes</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnSaleOfPropertyPlantEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Gain on Sale of Windcat Workboats</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromPropertyPlantAndEquipmentIncludingDepositsAndGainOnSale" xlink:type="locator" xlink:label="smhi_ProceedsFromPropertyPlantAndEquipmentIncludingDepositsAndGainOnSale" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromPropertyPlantAndEquipmentIncludingDepositsAndGainOnSale_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds from property, plant, and equipment, including deposits and gain on sale.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromPropertyPlantAndEquipmentIncludingDepositsAndGainOnSale" xlink:to="smhi_ProceedsFromPropertyPlantAndEquipmentIncludingDepositsAndGainOnSale_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfEquipmentSold" xlink:type="locator" xlink:label="smhi_NumberOfEquipmentSold" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the number of equipment sold.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfEquipmentSold" xlink:to="smhi_NumberOfEquipmentSold_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromDeposits" xlink:type="locator" xlink:label="smhi_ProceedsFromDeposits" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromDeposits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Amount of cash inflow for receipts of deposits.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromDeposits" xlink:to="smhi_ProceedsFromDeposits_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromPropertyPlantAndEquipmentIncludingDepositsAndGainOnSale_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from property, plant, and equipment, including deposits and gain on sale</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromPropertyPlantAndEquipmentIncludingDepositsAndGainOnSale_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Property Plant And Equipment Including Deposits And Gain On Sale</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of equipment sold</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Equipment Sold</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromSaleOfPropertyPlantAndEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Proceeds from sale of business</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromDeposits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from deposits</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromDeposits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Deposits</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ReducedOfDebtUnderCreditFacility" xlink:type="locator" xlink:label="smhi_ReducedOfDebtUnderCreditFacility" />
    <link:label xml:lang="en-US" xlink:label="smhi_ReducedOfDebtUnderCreditFacility_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Reduced of debt under credit facility.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ReducedOfDebtUnderCreditFacility" xlink:to="smhi_ReducedOfDebtUnderCreditFacility_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PropertyPlantEquipmentConsiderationTransferred" xlink:type="locator" xlink:label="smhi_PropertyPlantEquipmentConsiderationTransferred" />
    <link:label xml:lang="en-US" xlink:label="smhi_PropertyPlantEquipmentConsiderationTransferred_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Property plant equipment consideration transferred.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PropertyPlantEquipmentConsiderationTransferred" xlink:to="smhi_PropertyPlantEquipmentConsiderationTransferred_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ReducedOfDebtUnderCreditFacility_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reduced of debt under credit facility</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ReducedOfDebtUnderCreditFacility_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Reduced Of Debt Under Credit Facility</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PropertyPlantEquipmentConsiderationTransferred_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property plant equipment consideration transferred</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PropertyPlantEquipmentConsiderationTransferred_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Property Plant Equipment Consideration Transferred</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationMaximumAdditionalConsideration" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationMaximumAdditionalConsideration" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationMaximumAdditionalConsideration_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation maximum additional consideration.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationMaximumAdditionalConsideration" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationMaximumAdditionalConsideration_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PropertyPlantAndEquipmentNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net book value</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationMaximumAdditionalConsideration_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Additional consideration</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationMaximumAdditionalConsideration_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Maximum Additional Consideration</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentIncludingDeposits" xlink:type="locator" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentIncludingDeposits" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentIncludingDeposits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale, including deposits.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentIncludingDeposits" xlink:to="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentIncludingDeposits_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentExcludingDepositsForFutureVesselSales" xlink:type="locator" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentExcludingDepositsForFutureVesselSales" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentExcludingDepositsForFutureVesselSales_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The cash inflow from the sale of long-lived, physical assets that are used in the normal conduct of business to produce goods and services and not intended for resale, excluding deposits for the future sales of vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentExcludingDepositsForFutureVesselSales" xlink:to="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentExcludingDepositsForFutureVesselSales_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentIncludingDeposits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from sale of property, plant, and equipment, including deposits</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentIncludingDeposits_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Sale Of Property Plant And Equipment Including Deposits</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentExcludingDepositsForFutureVesselSales_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from sale of property, plant, and equipment, excluding deposits for future vessel sales</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentExcludingDepositsForFutureVesselSales_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Sale Of Property Plant And Equipment Excluding Deposits For Future Vessel Sales</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfEquipmentRemovedFromService" xlink:type="locator" xlink:label="smhi_NumberOfEquipmentRemovedFromService" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentRemovedFromService_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the number of equipment removed from service.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfEquipmentRemovedFromService" xlink:to="smhi_NumberOfEquipmentRemovedFromService_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentRemovedFromService_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Removed from service</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentRemovedFromService_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Equipment Removed From Service</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfEquipmentRemovedFromServiceExcludesFromMajorEquipmentDispositions" xlink:type="locator" xlink:label="smhi_NumberOfEquipmentRemovedFromServiceExcludesFromMajorEquipmentDispositions" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentRemovedFromServiceExcludesFromMajorEquipmentDispositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of equipment removed from service excludes from major equipment dispositions.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfEquipmentRemovedFromServiceExcludesFromMajorEquipmentDispositions" xlink:to="smhi_NumberOfEquipmentRemovedFromServiceExcludesFromMajorEquipmentDispositions_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfEquipmentHeldForSaleExcludedFromMajorEquipmentDispositions" xlink:type="locator" xlink:label="smhi_NumberOfEquipmentHeldForSaleExcludedFromMajorEquipmentDispositions" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentHeldForSaleExcludedFromMajorEquipmentDispositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of equipment held for sale excluded from major equipment dispositions.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfEquipmentHeldForSaleExcludedFromMajorEquipmentDispositions" xlink:to="smhi_NumberOfEquipmentHeldForSaleExcludedFromMajorEquipmentDispositions_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentRemovedFromServiceExcludesFromMajorEquipmentDispositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of Equipment Removed from Service Excludes from Major Equipment Dispositions</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentRemovedFromServiceExcludesFromMajorEquipmentDispositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Equipment Removed From Service Excludes From Major Equipment Dispositions</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentHeldForSaleExcludedFromMajorEquipmentDispositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of equipment held for sale excluded from major equipment dispositions</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentHeldForSaleExcludedFromMajorEquipmentDispositions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Equipment Held For Sale Excluded From Major Equipment Dispositions</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACORMarlinLLCMember" xlink:type="locator" xlink:label="smhi_SEACORMarlinLLCMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarlinLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Related to the entity SEACOR Marlin LLC.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACORMarlinLLCMember" xlink:to="smhi_SEACORMarlinLLCMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarlinLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Marlin LLC</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarlinLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Marlin L L C [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_MEXMAROffshoreMember" xlink:type="locator" xlink:label="smhi_MEXMAROffshoreMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_MEXMAROffshoreMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">MEXMAR offshore [Member].</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_MEXMAROffshoreMember" xlink:to="smhi_MEXMAROffshoreMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_MEXMAROffshoreMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">MEXMAR Offshore</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_MEXMAROffshoreMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">M E X M A R Offshore [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OffshoreVesselHoldingsMember" xlink:type="locator" xlink:label="smhi_OffshoreVesselHoldingsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreVesselHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to Offshore Vessel Holdings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OffshoreVesselHoldingsMember" xlink:to="smhi_OffshoreVesselHoldingsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreVesselHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Offshore Vessel Holdings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreVesselHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Offshore Vessel Holdings [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OtherOffshoreMarineServicesJointVenturesMember" xlink:type="locator" xlink:label="smhi_OtherOffshoreMarineServicesJointVenturesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherOffshoreMarineServicesJointVenturesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to other offshore marine services joint ventures.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OtherOffshoreMarineServicesJointVenturesMember" xlink:to="smhi_OtherOffshoreMarineServicesJointVenturesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherOffshoreMarineServicesJointVenturesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Offshore Marine Services Joint Ventures</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OtherOffshoreMarineServicesJointVenturesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Offshore Marine Services Joint Ventures [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AllOtherExcludingMexMarFalconGlobalSeaCatCrewzerAndSeaCatCrewzerIIMember" xlink:type="locator" xlink:label="smhi_AllOtherExcludingMexMarFalconGlobalSeaCatCrewzerAndSeaCatCrewzerIIMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_AllOtherExcludingMexMarFalconGlobalSeaCatCrewzerAndSeaCatCrewzerIIMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">All other excluding mexMar falcon global sea cat crewzer and sea cat crewzer II.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_AllOtherExcludingMexMarFalconGlobalSeaCatCrewzerAndSeaCatCrewzerIIMember" xlink:to="smhi_AllOtherExcludingMexMarFalconGlobalSeaCatCrewzerAndSeaCatCrewzerIIMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_AllOtherExcludingMexMarFalconGlobalSeaCatCrewzerAndSeaCatCrewzerIIMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">All Other Excluding MexMar, Falcon Global, Sea-Cat Crewzer and Sea-Cat Crewzer II</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AllOtherExcludingMexMarFalconGlobalSeaCatCrewzerAndSeaCatCrewzerIIMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">All Other Excluding Mex Mar Falcon Global Sea Cat Crewzer And Sea Cat Crewzer I I [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Method Investment, Nonconsolidated Investee</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis" xlink:to="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Nonconsolidated Investee [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Method Investment, Nonconsolidated Investee</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain" xlink:to="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Nonconsolidated Investee [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Method Investment, Nonconsolidated Investee or Group of Investees</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember" xlink:to="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentNonconsolidatedInvesteeOrGroupOfInvesteesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Nonconsolidated Investee Or Group Of Investees [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentOwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveLabel">Ownership percentage</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investments at equity</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_MexmarOffshoreInternationalMember" xlink:type="locator" xlink:label="smhi_MexmarOffshoreInternationalMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_MexmarOffshoreInternationalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Mexmar offshore international.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_MexmarOffshoreInternationalMember" xlink:to="smhi_MexmarOffshoreInternationalMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_MexmarOffshoreInternationalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Mexmar Offshore International</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_MexmarOffshoreInternationalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Mexmar Offshore International [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeneralPartnerMember" xlink:type="locator" xlink:label="us-gaap_GeneralPartnerMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeneralPartnerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">General Partner</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeneralPartnerMember" xlink:to="us-gaap_GeneralPartnerMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeneralPartnerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">General Partner [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByAssetClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByAssetClassAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueByAssetClassAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Asset Class</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByAssetClassAxis" xlink:to="us-gaap_FairValueByAssetClassAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueByAssetClassAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value By Asset Class [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Asset Class</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain" xlink:to="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueAssetsMeasuredOnRecurringBasisUnobservableInputReconciliationByAssetClassDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Assets Measured On Recurring Basis Unobservable Input Reconciliation By Asset Class [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentsMember" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Method Investments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentsMember" xlink:to="us-gaap_EquityMethodInvestmentsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investments [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentCompanyDividendDistribution" xlink:type="locator" xlink:label="us-gaap_InvestmentCompanyDividendDistribution" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentCompanyDividendDistribution_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment, distribution exceeded</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentCompanyDividendDistribution" xlink:to="us-gaap_InvestmentCompanyDividendDistribution_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentCompanyDividendDistribution_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment Company Dividend Distribution</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current assets</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsNoncurrent" xlink:type="locator" xlink:label="us-gaap_AssetsNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Noncurrent assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsNoncurrent" xlink:to="us-gaap_AssetsNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets Noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Current liabilities</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Noncurrent liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesNoncurrent" xlink:to="us-gaap_LiabilitiesNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Noncurrent</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndAdministrative" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndAdministrative" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndAdministrative_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity method investment summarized financial information operating and administrative.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndAdministrative" xlink:to="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndAdministrative_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentSummarizedFinancialInformationDepreciation" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationDepreciation" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationDepreciation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity method investment summarized financial information depreciation.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentSummarizedFinancialInformationDepreciation" xlink:to="smhi_EquityMethodInvestmentSummarizedFinancialInformationDepreciation_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingCostsAndExpenses" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingCostsAndExpenses" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingCostsAndExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity method investment summarized financial information operating costs and expenses.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingCostsAndExpenses" xlink:to="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingCostsAndExpenses_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentSummarizedFinancialInformationIncomeLossOnAssetDispositionsAndImpairmentsNet" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationIncomeLossOnAssetDispositionsAndImpairmentsNet" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationIncomeLossOnAssetDispositionsAndImpairmentsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The amount of income (loss) on asset dispositions and impairments reported by an equity method investment of the entity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentSummarizedFinancialInformationIncomeLossOnAssetDispositionsAndImpairmentsNet" xlink:to="smhi_EquityMethodInvestmentSummarizedFinancialInformationIncomeLossOnAssetDispositionsAndImpairmentsNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndAdministrative_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating and administrative</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingAndAdministrative_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Summarized Financial Information Operating And Administrative</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationDepreciation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationDepreciation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Summarized Financial Information Depreciation</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingCostsAndExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Costs and expenses</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationOperatingCostsAndExpenses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Summarized Financial Information Operating Costs And Expenses</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationIncomeLossOnAssetDispositionsAndImpairmentsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loss on Asset Dispositions and Impairments, Net</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentSummarizedFinancialInformationIncomeLossOnAssetDispositionsAndImpairmentsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Summarized Financial Information Income Loss On Asset Dispositions And Impairments Net</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeLossFromContinuingOperationsIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Operating (Loss) Income</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentsUnrealizedIntercompanyProfitLossNotEliminatedAmount" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentsUnrealizedIntercompanyProfitLossNotEliminatedAmount" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentsUnrealizedIntercompanyProfitLossNotEliminatedAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity method investments unrealized intercompany profit loss not eliminated amount.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentsUnrealizedIntercompanyProfitLossNotEliminatedAmount" xlink:to="smhi_EquityMethodInvestmentsUnrealizedIntercompanyProfitLossNotEliminatedAmount_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_UPOffshoresMember" xlink:type="locator" xlink:label="smhi_UPOffshoresMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_UPOffshoresMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">UP Offshore&#8217;s.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_UPOffshoresMember" xlink:to="smhi_UPOffshoresMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_UPOffshoresMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">UP Offshore</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_UPOffshoresMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">U P Offshores [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OffshoreVesselHoldingsAndOperadoraProductoraYExploradoraMexicanaSADeCVMember" xlink:type="locator" xlink:label="smhi_OffshoreVesselHoldingsAndOperadoraProductoraYExploradoraMexicanaSADeCVMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreVesselHoldingsAndOperadoraProductoraYExploradoraMexicanaSADeCVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Offshore Vessel Holdings and Operadora Productora y Exploradora Mexicana S.A. de C.V.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OffshoreVesselHoldingsAndOperadoraProductoraYExploradoraMexicanaSADeCVMember" xlink:to="smhi_OffshoreVesselHoldingsAndOperadoraProductoraYExploradoraMexicanaSADeCVMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreVesselHoldingsAndOperadoraProductoraYExploradoraMexicanaSADeCVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">OVH and OPEM</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OffshoreVesselHoldingsAndOperadoraProductoraYExploradoraMexicanaSADeCVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Offshore Vessel Holdings And Operadora Productora Y Exploradora Mexicana S A De C V [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_JackUpDrillingsMember" xlink:type="locator" xlink:label="smhi_JackUpDrillingsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_JackUpDrillingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Jack up drillings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_JackUpDrillingsMember" xlink:to="smhi_JackUpDrillingsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_JackUpDrillingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Jack up Drillings [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_JackUpDrillingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Jack Up Drillings [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_FSVOffshoreSupportVesselsMember" xlink:type="locator" xlink:label="smhi_FSVOffshoreSupportVesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_FSVOffshoreSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to FSV offshore support vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_FSVOffshoreSupportVesselsMember" xlink:to="smhi_FSVOffshoreSupportVesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_FSVOffshoreSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">F S V Offshore Support Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FSVOffshoreSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">F S V Offshore Support Vessels [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentsUnrealizedIntercompanyProfitLossNotEliminatedAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidated retained earnings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentsUnrealizedIntercompanyProfitLossNotEliminatedAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investments Unrealized Intercompany Profit Loss Not Eliminated Amount</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfEquipmentOperated" xlink:type="locator" xlink:label="smhi_NumberOfEquipmentOperated" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentOperated_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the number of equipment operated.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfEquipmentOperated" xlink:to="smhi_NumberOfEquipmentOperated_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentOperated_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of equipment operated</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentOperated_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Equipment Operated</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromEquityMethodInvestmentDividendsOrDistributionsReturnOfCapital_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Capital distributions from equity investees</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RevenueFromRelatedParties" xlink:type="locator" xlink:label="us-gaap_RevenueFromRelatedParties" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueFromRelatedParties_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Revenue from related parties</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RevenueFromRelatedParties" xlink:to="us-gaap_RevenueFromRelatedParties_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueFromRelatedParties_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Revenue From Related Parties</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentOwnershipPercentSold" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentOwnershipPercentSold" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipPercentSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The percentage ownership of equity method investments that was sold during the period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentOwnershipPercentSold" xlink:to="smhi_EquityMethodInvestmentOwnershipPercentSold_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipPercentSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity method investment, ownership, percent sold</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipPercentSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Ownership Percent Sold</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromDivestitureOfInterestInJointVenture" xlink:type="locator" xlink:label="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from divestiture of interest in joint venture</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture" xlink:to="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromDivestitureOfInterestInJointVenture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Divestiture Of Interest In Joint Venture</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainLossOnSaleOfBusiness" xlink:type="locator" xlink:label="us-gaap_GainLossOnSaleOfBusiness" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnSaleOfBusiness_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain (loss) on disposition of business</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainLossOnSaleOfBusiness" xlink:to="us-gaap_GainLossOnSaleOfBusiness_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnSaleOfBusiness_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Gain Loss On Sale Of Business</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfVesselSold" xlink:type="locator" xlink:label="smhi_NumberOfVesselSold" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of vessel sold.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfVesselSold" xlink:to="smhi_NumberOfVesselSold_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfGainFromEquityEarnings" xlink:type="locator" xlink:label="smhi_PercentageOfGainFromEquityEarnings" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfGainFromEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of gain from equity earnings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfGainFromEquityEarnings" xlink:to="smhi_PercentageOfGainFromEquityEarnings_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of vessels sold</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfVesselSold_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Vessel Sold</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentSoldCarryingAmount" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentSoldCarryingAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentSoldCarryingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentSoldCarryingAmount" xlink:to="us-gaap_EquityMethodInvestmentSoldCarryingAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentSoldCarryingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Sold Carrying Amount</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfGainFromEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of gain from equity earnings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfGainFromEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Gain From Equity Earnings</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain on equity earnings</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal" xlink:to="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentRealizedGainLossOnDisposal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Realized Gain Loss On Disposal</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentOwnershipPercentageTransferred" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentOwnershipPercentageTransferred" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipPercentageTransferred_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity method investment ownership percentage transferred.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentOwnershipPercentageTransferred" xlink:to="smhi_EquityMethodInvestmentOwnershipPercentageTransferred_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityInterestTransferredConsiderationAndTransactionFee" xlink:type="locator" xlink:label="smhi_EquityInterestTransferredConsiderationAndTransactionFee" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityInterestTransferredConsiderationAndTransactionFee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity interest transferred consideration and transaction fee.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityInterestTransferredConsiderationAndTransactionFee" xlink:to="smhi_EquityInterestTransferredConsiderationAndTransactionFee_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EquityMethodInvestmentDividendsOrDistributions" xlink:type="locator" xlink:label="us-gaap_EquityMethodInvestmentDividendsOrDistributions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentDividendsOrDistributions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Received distribution from joint ventures</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EquityMethodInvestmentDividendsOrDistributions" xlink:to="us-gaap_EquityMethodInvestmentDividendsOrDistributions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestmentDividendsOrDistributions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Dividends Or Distributions</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipPercentageTransferred_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transferred equity interest</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipPercentageTransferred_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Ownership Percentage Transferred</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityInterestTransferredConsiderationAndTransactionFee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity interest transferred consideration and transaction fee.</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityInterestTransferredConsiderationAndTransactionFee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Interest Transferred Consideration And Transaction Fee</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DebtInstrumentForgivenessOfAccruedInterest" xlink:type="locator" xlink:label="smhi_DebtInstrumentForgivenessOfAccruedInterest" />
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentForgivenessOfAccruedInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt instrument forgiveness of accrued interest.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DebtInstrumentForgivenessOfAccruedInterest" xlink:to="smhi_DebtInstrumentForgivenessOfAccruedInterest_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_FinancingAgreement" xlink:type="locator" xlink:label="smhi_FinancingAgreement" />
    <link:label xml:lang="en-US" xlink:label="smhi_FinancingAgreement_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Financing agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_FinancingAgreement" xlink:to="smhi_FinancingAgreement_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:type="locator" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByParent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByParent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Noncontrolling Interest, ownership percentage by parent</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestOwnershipPercentageByParent" xlink:to="us-gaap_MinorityInterestOwnershipPercentageByParent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByParent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Minority Interest Ownership Percentage By Parent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentsToAcquireInterestInJointVenture" xlink:type="locator" xlink:label="us-gaap_PaymentsToAcquireInterestInJointVenture" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PaymentsToAcquireInterestInJointVenture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payments to acquire interest in joint venture</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentsToAcquireInterestInJointVenture" xlink:to="us-gaap_PaymentsToAcquireInterestInJointVenture_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PaymentsToAcquireInterestInJointVenture_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Payments To Acquire Interest In Joint Venture</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PartnersCapitalAccountContributions" xlink:type="locator" xlink:label="us-gaap_PartnersCapitalAccountContributions" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PartnersCapitalAccountContributions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Contributed capital</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PartnersCapitalAccountContributions" xlink:to="us-gaap_PartnersCapitalAccountContributions_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PartnersCapitalAccountContributions_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Partners Capital Account Contributions</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FinancingAgreement_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Financing agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FinancingAgreement_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Financing Agreement</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfDebt" xlink:type="locator" xlink:label="us-gaap_RepaymentsOfDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RepaymentsOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Settled loan</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfDebt" xlink:to="us-gaap_RepaymentsOfDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RepaymentsOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Repayments Of Debt</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EarlyRepaymentOfSeniorDebt" xlink:type="locator" xlink:label="us-gaap_EarlyRepaymentOfSeniorDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EarlyRepaymentOfSeniorDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Early repayment of debt</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EarlyRepaymentOfSeniorDebt" xlink:to="us-gaap_EarlyRepaymentOfSeniorDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EarlyRepaymentOfSeniorDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Early Repayment Of Senior Debt</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentForgivenessOfAccruedInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Forgiveness of accrued interest</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentForgivenessOfAccruedInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Forgiveness Of Accrued Interest</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PaymentForManagementFee" xlink:type="locator" xlink:label="us-gaap_PaymentForManagementFee" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PaymentForManagementFee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Management fees</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PaymentForManagementFee" xlink:to="us-gaap_PaymentForManagementFee_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PaymentForManagementFee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Payment For Management Fee</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ReturnOfCapitalEquityMethodInvestment" xlink:type="locator" xlink:label="smhi_ReturnOfCapitalEquityMethodInvestment" />
    <link:label xml:lang="en-US" xlink:label="smhi_ReturnOfCapitalEquityMethodInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Return of capital equity method investment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ReturnOfCapitalEquityMethodInvestment" xlink:to="smhi_ReturnOfCapitalEquityMethodInvestment_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ReturnOfCapitalEquityMethodInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Return of capital equity method investment</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ReturnOfCapitalEquityMethodInvestment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Return Of Capital Equity Method Investment</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ConstructionReserveFundsCommitmentPeriod" xlink:type="locator" xlink:label="smhi_ConstructionReserveFundsCommitmentPeriod" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundsCommitmentPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Construction reserve funds commitment period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ConstructionReserveFundsCommitmentPeriod" xlink:to="smhi_ConstructionReserveFundsCommitmentPeriod_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfExtensionPeriod" xlink:type="locator" xlink:label="smhi_NumberOfExtensionPeriod" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfExtensionPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of extension period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfExtensionPeriod" xlink:to="smhi_NumberOfExtensionPeriod_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ConstructionReserveFundsExtensionPeriod" xlink:type="locator" xlink:label="smhi_ConstructionReserveFundsExtensionPeriod" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundsExtensionPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Construction reserve funds extension period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ConstructionReserveFundsExtensionPeriod" xlink:to="smhi_ConstructionReserveFundsExtensionPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundsCommitmentPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Construction reserve funds commitment period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundsCommitmentPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Construction Reserve Funds Commitment Period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfExtensionPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of extension period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfExtensionPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Extension Period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundsExtensionPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Construction reserve funds extension period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundsExtensionPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Construction Reserve Funds Extension Period</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ShortTermConstructionReserveFunds" xlink:type="locator" xlink:label="smhi_ShortTermConstructionReserveFunds" />
    <link:label xml:lang="en-US" xlink:label="smhi_ShortTermConstructionReserveFunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Short term construction reserve funds.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ShortTermConstructionReserveFunds" xlink:to="smhi_ShortTermConstructionReserveFunds_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ConstructionReserveFundWithdrawals" xlink:type="locator" xlink:label="smhi_ConstructionReserveFundWithdrawals" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundWithdrawals_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the amount of withdrawals for construction reserve fund.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ConstructionReserveFundWithdrawals" xlink:to="smhi_ConstructionReserveFundWithdrawals_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ShortTermConstructionReserveFunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term construction reserve funds</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ShortTermConstructionReserveFunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Short Term Construction Reserve Funds</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundWithdrawals_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Construction reserve fund withdrawals</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConstructionReserveFundWithdrawals_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Construction Reserve Fund Withdrawals</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CumulativeEffectOnRetainedEarningsBeforeTax" xlink:type="locator" xlink:label="smhi_CumulativeEffectOnRetainedEarningsBeforeTax" />
    <link:label xml:lang="en-US" xlink:label="smhi_CumulativeEffectOnRetainedEarningsBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cumulative effect on retained earnings before tax.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CumulativeEffectOnRetainedEarningsBeforeTax" xlink:to="smhi_CumulativeEffectOnRetainedEarningsBeforeTax_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CumulativeEffectOnRetainedEarningsTax" xlink:type="locator" xlink:label="smhi_CumulativeEffectOnRetainedEarningsTax" />
    <link:label xml:lang="en-US" xlink:label="smhi_CumulativeEffectOnRetainedEarningsTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cumulative effect on retained earnings tax.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CumulativeEffectOnRetainedEarningsTax" xlink:to="smhi_CumulativeEffectOnRetainedEarningsTax_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeLeaseDescriptionTable" xlink:type="locator" xlink:label="us-gaap_LesseeLeaseDescriptionTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeLeaseDescriptionTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lessee Lease Description [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeLeaseDescriptionTable" xlink:to="us-gaap_LesseeLeaseDescriptionTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeLeaseDescriptionTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Lease Description [Table]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OtherEquipmentMember" xlink:type="locator" xlink:label="smhi_OtherEquipmentMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Member stands for other equipment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OtherEquipmentMember" xlink:to="smhi_OtherEquipmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Equipment</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OtherEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Equipment [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MachineryAndEquipmentMember" xlink:type="locator" xlink:label="us-gaap_MachineryAndEquipmentMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Machinery and Equipment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MachineryAndEquipmentMember" xlink:to="us-gaap_MachineryAndEquipmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MachineryAndEquipmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Machinery And Equipment [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeLeaseDescriptionLineItems" xlink:type="locator" xlink:label="us-gaap_LesseeLeaseDescriptionLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeLeaseDescriptionLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lessee Lease Description [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeLeaseDescriptionLineItems" xlink:to="us-gaap_LesseeLeaseDescriptionLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeLeaseDescriptionLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Lease Description [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CumulativeEffectOnRetainedEarningsBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cumulative effect on retained earnings, Before tax</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CumulativeEffectOnRetainedEarningsBeforeTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cumulative Effect On Retained Earnings Before Tax</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CumulativeEffectOnRetainedEarningsTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cumulative effect on retained earnings, Tax</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CumulativeEffectOnRetainedEarningsTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cumulative Effect On Retained Earnings Tax</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfOperatingLeasesOnEquipment" xlink:type="locator" xlink:label="smhi_NumberOfOperatingLeasesOnEquipment" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfOperatingLeasesOnEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of operating leases on equipment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfOperatingLeasesOnEquipment" xlink:to="smhi_NumberOfOperatingLeasesOnEquipment_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfOperatingLeasesOnEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of operating leases on equipment</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfOperatingLeasesOnEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Operating Leases On Equipment</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseTermOfContract" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseTermOfContract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseTermOfContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease, lease terms (in duration)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseTermOfContract" xlink:to="us-gaap_LesseeOperatingLeaseTermOfContract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseTermOfContract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Term Of Contract</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Liabilities Payments Due [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Next Twelve Months</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Year Two</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Year Three</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Year Four</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due Year Five</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Years subsequent to 2026</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due After Year Five</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Operating lease payments due</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityPaymentsDue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Payments Due</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:type="locator" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Interest component</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LesseeOperatingLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lessee Operating Lease Liability Undiscounted Excess Amount</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total operating leases</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance Leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract" xlink:to="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilitiesPaymentsDueAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liabilities Payments Due [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Payments Due Next Twelve Months</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Payments Due Year Two</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Payments Due Year Three</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Payments Due Year Four</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Payments Due Year Five</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Years subsequent to 2026</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDueAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Payments Due After Year Five</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total finance leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityPaymentsDue" xlink:to="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityPaymentsDue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Payments Due</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Interest component</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount" xlink:to="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiabilityUndiscountedExcessAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability Undiscounted Excess Amount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseLiability" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseLiability" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Finance Leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseLiability" xlink:to="us-gaap_FinanceLeaseLiability_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Liability</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_FinanceLeaseCostsAbstract" xlink:type="locator" xlink:label="smhi_FinanceLeaseCostsAbstract" />
    <link:label xml:lang="en-US" xlink:label="smhi_FinanceLeaseCostsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Finance lease costs.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_FinanceLeaseCostsAbstract" xlink:to="smhi_FinanceLeaseCostsAbstract_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseCost" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease cost</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseCost" xlink:to="us-gaap_OperatingLeaseCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Cost</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FinanceLeaseCostsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Finance lease cost:</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FinanceLeaseCostsAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Costs [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Amortization of finance lease asset</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseRightOfUseAssetAmortization" xlink:to="us-gaap_FinanceLeaseRightOfUseAssetAmortization_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseRightOfUseAssetAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Right Of Use Asset Amortization</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseInterestExpense" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseInterestExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseInterestExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest on lease liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseInterestExpense" xlink:to="us-gaap_FinanceLeaseInterestExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseInterestExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Interest Expense</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShortTermLeaseCost" xlink:type="locator" xlink:label="us-gaap_ShortTermLeaseCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShortTermLeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Short-term lease costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShortTermLeaseCost" xlink:to="us-gaap_ShortTermLeaseCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShortTermLeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Short Term Lease Cost</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LeaseCost" xlink:type="locator" xlink:label="us-gaap_LeaseCost" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total lease expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LeaseCost" xlink:to="us-gaap_LeaseCost_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LeaseCost_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lease Cost</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeasePayments" xlink:type="locator" xlink:label="us-gaap_OperatingLeasePayments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeasePayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Operating cash flows from operating leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeasePayments" xlink:to="us-gaap_OperatingLeasePayments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeasePayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Payments</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeasePrincipalPayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Financing cash outflows from finance leases</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:type="locator" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets obtained for operating lease liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForOperatingLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Right Of Use Asset Obtained In Exchange For Operating Lease Liability</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:type="locator" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Right-of-use assets obtained for finance lease liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability" xlink:to="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RightOfUseAssetObtainedInExchangeForFinanceLeaseLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Right Of Use Asset Obtained In Exchange For Finance Lease Liability</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average remaining lease term, in years - operating leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Weighted Average Remaining Lease Term1</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average remaining lease term, in years - finance leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1" xlink:to="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseWeightedAverageRemainingLeaseTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Weighted Average Remaining Lease Term1</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average discount rate - operating leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseWeightedAverageDiscountRatePercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Weighted Average Discount Rate Percent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:type="locator" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Weighted average discount - finance leases</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent" xlink:to="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FinanceLeaseWeightedAverageDiscountRatePercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Finance Lease Weighted Average Discount Rate Percent</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfOperatingLeasesImpaired" xlink:type="locator" xlink:label="smhi_NumberOfOperatingLeasesImpaired" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfOperatingLeasesImpaired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents number of operating leases impaired.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfOperatingLeasesImpaired" xlink:to="smhi_NumberOfOperatingLeasesImpaired_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLeaseImpairmentLoss" xlink:type="locator" xlink:label="us-gaap_OperatingLeaseImpairmentLoss" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseImpairmentLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating lease, impairment loss</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLeaseImpairmentLoss" xlink:to="us-gaap_OperatingLeaseImpairmentLoss_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLeaseImpairmentLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Lease Impairment Loss</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfOperatingLeasesImpaired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of operating leases impaired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfOperatingLeasesImpaired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Operating Leases Impaired</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTable" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTable" xlink:to="us-gaap_DebtInstrumentTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Table]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ConvertibleSeniorNotesMember" xlink:type="locator" xlink:label="smhi_ConvertibleSeniorNotesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Member represents convertible senior notes.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ConvertibleSeniorNotesMember" xlink:to="smhi_ConvertibleSeniorNotesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Senior Notes</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Senior Notes [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACORMarineForeignHoldingsCreditFacilityMember" xlink:type="locator" xlink:label="smhi_SEACORMarineForeignHoldingsCreditFacilityMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineForeignHoldingsCreditFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Member stands for SEACOR Marine Foreign Holdings Credit Facility.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACORMarineForeignHoldingsCreditFacilityMember" xlink:to="smhi_SEACORMarineForeignHoldingsCreditFacilityMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineForeignHoldingsCreditFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Marine Foreign Holdings Credit Facility</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORMarineForeignHoldingsCreditFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Marine Foreign Holdings Credit Facility [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SeaCatCrewzerIIITermLoanFacilityMember" xlink:type="locator" xlink:label="smhi_SeaCatCrewzerIIITermLoanFacilityMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SeaCatCrewzerIIITermLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information about Sea-Cat Crewzer III term loan facility.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SeaCatCrewzerIIITermLoanFacilityMember" xlink:to="smhi_SeaCatCrewzerIIITermLoanFacilityMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SeaCatCrewzerIIITermLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sea-Cat Crewzer III Term Loan Facility</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SeaCatCrewzerIIITermLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sea Cat Crewzer I I I Term Loan Facility [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember" xlink:type="locator" xlink:label="smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Member stands for SEACOR Offshore Delta (formerly known as SEACOSCO) Acquisition Debt.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember" xlink:to="smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Offshore Delta (f/k/a SEACOSCO) Acquisition Debt</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Offshore Delta Formerly Known As S E A C O S C O Acquisition Debt [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember" xlink:type="locator" xlink:label="smhi_SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Member stands for SEACOR Delta (formerly known as SEACOSCO) Shipyard Financing.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember" xlink:to="smhi_SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Delta (f/k/a SEACOSCO) Shipyard Financing</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Delta Formerly Known As S E A C O S C O Shipyard Financing [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACORAlpineShipyardFinancingMember" xlink:type="locator" xlink:label="smhi_SEACORAlpineShipyardFinancingMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORAlpineShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Member stands for SEACOR Alpine Shipyard Financing.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACORAlpineShipyardFinancingMember" xlink:to="smhi_SEACORAlpineShipyardFinancingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORAlpineShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Alpine Shipyard Financing</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORAlpineShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Alpine Shipyard Financing [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACOR88888TermLoanMember" xlink:type="locator" xlink:label="smhi_SEACOR88888TermLoanMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOR88888TermLoanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Member stands for SEACOR 88/888 term loan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACOR88888TermLoanMember" xlink:to="smhi_SEACOR88888TermLoanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOR88888TermLoanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR 88/888 Term Loan</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOR88888TermLoanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R88888 Term Loan [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TarahumaraShipyardFinancingMember" xlink:type="locator" xlink:label="smhi_TarahumaraShipyardFinancingMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TarahumaraShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Tarahumara shipyard financing.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TarahumaraShipyardFinancingMember" xlink:to="smhi_TarahumaraShipyardFinancingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TarahumaraShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tarahumara Shipyard Financing</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TarahumaraShipyardFinancingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Tarahumara Shipyard Financing [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SeacorOffshoreOSVMember" xlink:type="locator" xlink:label="smhi_SeacorOffshoreOSVMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SeacorOffshoreOSVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Seacor Offshore OSV.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SeacorOffshoreOSVMember" xlink:to="smhi_SeacorOffshoreOSVMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SeacorOffshoreOSVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Offshore OSV</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SeacorOffshoreOSVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Seacor Offshore O S V [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_FalconGlobalUSARevolverMember" xlink:type="locator" xlink:label="smhi_FalconGlobalUSARevolverMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalUSARevolverMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents a member containing information about Falcon Global USA Revolver facilitis.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_FalconGlobalUSARevolverMember" xlink:to="smhi_FalconGlobalUSARevolverMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalUSARevolverMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Falcon Global USA Revolver</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalUSARevolverMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Falcon Global U S A Revolver [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_WindcatWorkboatsFacilitiesMember" xlink:type="locator" xlink:label="smhi_WindcatWorkboatsFacilitiesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsFacilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Mebers stands for Windcat workboats facilities.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_WindcatWorkboatsFacilitiesMember" xlink:to="smhi_WindcatWorkboatsFacilitiesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsFacilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Windcat Workboats Facilities</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsFacilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Windcat Workboats Facilities [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RecourseStatusAxis" xlink:type="locator" xlink:label="us-gaap_RecourseStatusAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecourseStatusAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recourse Status</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecourseStatusAxis" xlink:to="us-gaap_RecourseStatusAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecourseStatusAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recourse Status [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RecourseStatusDomain" xlink:type="locator" xlink:label="us-gaap_RecourseStatusDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecourseStatusDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recourse Status</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecourseStatusDomain" xlink:to="us-gaap_RecourseStatusDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecourseStatusDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recourse Status [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RecourseMember" xlink:type="locator" xlink:label="us-gaap_RecourseMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecourseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recourse Long-Term Debt</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RecourseMember" xlink:to="us-gaap_RecourseMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RecourseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Recourse [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonrecourseMember" xlink:type="locator" xlink:label="us-gaap_NonrecourseMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NonrecourseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-Recourse Long-Term Debt</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonrecourseMember" xlink:to="us-gaap_NonrecourseMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NonrecourseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Nonrecourse [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentLineItems" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentLineItems" xlink:to="us-gaap_DebtInstrumentLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument [Line Items]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentCarryingAmount" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentCarryingAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term Debt, Gross</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentCarryingAmount" xlink:to="us-gaap_DebtInstrumentCarryingAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Carrying Amount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtCurrent" xlink:type="locator" xlink:label="us-gaap_LongTermDebtCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Current portion due within one year</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtCurrent" xlink:to="us-gaap_LongTermDebtCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentUnamortizedDiscount" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Unamortized debt discount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentUnamortizedDiscount" xlink:to="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentUnamortizedDiscount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Unamortized Discount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFinanceCostsNoncurrentNet" xlink:type="locator" xlink:label="us-gaap_DeferredFinanceCostsNoncurrentNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredFinanceCostsNoncurrentNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Deferred financing costs</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFinanceCostsNoncurrentNet" xlink:to="us-gaap_DeferredFinanceCostsNoncurrentNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredFinanceCostsNoncurrentNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Finance Costs Noncurrent Net</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtNoncurrent" xlink:type="locator" xlink:label="us-gaap_LongTermDebtNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term debt, less current portion</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtNoncurrent" xlink:to="us-gaap_LongTermDebtNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Noncurrent</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACOSCOOffshoreLLCMember" xlink:type="locator" xlink:label="smhi_SEACOSCOOffshoreLLCMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOSCOOffshoreLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to SEACOSCO Offshore LLC.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACOSCOOffshoreLLCMember" xlink:to="smhi_SEACOSCOOffshoreLLCMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOSCOOffshoreLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOSCO Offshore LLC</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOSCOOffshoreLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O S C O Offshore L L C [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfEquipmentAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Number of vessels acquired</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2022</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInNextTwelveMonths_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Maturities Repayments Of Principal In Next Twelve Months</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2023</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Maturities Repayments Of Principal In Year Two</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2024</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Maturities Repayments Of Principal In Year Three</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2025</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Maturities Repayments Of Principal In Year Four</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2026</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalInYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Maturities Repayments Of Principal In Year Five</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:type="locator" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Years subsequent to 2026</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive" xlink:to="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtMaturitiesRepaymentsOfPrincipalAfterYearFive_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Maturities Repayments Of Principal After Year Five</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentCarryingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Long-term Debt, Gross</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LineOfCreditFacilityAssumedAndGuaranteed" xlink:type="locator" xlink:label="smhi_LineOfCreditFacilityAssumedAndGuaranteed" />
    <link:label xml:lang="en-US" xlink:label="smhi_LineOfCreditFacilityAssumedAndGuaranteed_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Line of credit facility assumed and guaranteed.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LineOfCreditFacilityAssumedAndGuaranteed" xlink:to="smhi_LineOfCreditFacilityAssumedAndGuaranteed_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TermLoanToAcquireOneVesselMember" xlink:type="locator" xlink:label="smhi_TermLoanToAcquireOneVesselMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TermLoanToAcquireOneVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Term loan to acquire one vessel.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TermLoanToAcquireOneVesselMember" xlink:to="smhi_TermLoanToAcquireOneVesselMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TermLoanToAcquireOneVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term Loan to Acquire One Vessel</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TermLoanToAcquireOneVesselMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Term Loan To Acquire One Vessel [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ConditionalPayoffAgreementMember" xlink:type="locator" xlink:label="smhi_ConditionalPayoffAgreementMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConditionalPayoffAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Conditional payoff agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ConditionalPayoffAgreementMember" xlink:to="smhi_ConditionalPayoffAgreementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConditionalPayoffAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Conditional Payoff Agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConditionalPayoffAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Conditional Payoff Agreement [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TermAndRevolvingLoanFacilityMember" xlink:type="locator" xlink:label="smhi_TermAndRevolvingLoanFacilityMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TermAndRevolvingLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Term and revolving loan facility.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TermAndRevolvingLoanFacilityMember" xlink:to="smhi_TermAndRevolvingLoanFacilityMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TermAndRevolvingLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term and Revolving Loan Facility</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TermAndRevolvingLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Term And Revolving Loan Facility [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument, Redemption, Period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodAxis" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Redemption Period [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Instrument, Redemption, Period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodDomain" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Redemption Period [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodOneMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Paid at Signing of Conditional Payoff Agreement</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodOneMember" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodOneMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Redemption Period One [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodTwoMember" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodTwoMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Paid Using Hull and Machinery Insurance Proceeds</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodTwoMember" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Redemption Period Two [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentRedemptionPeriodThreeMember" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodThreeMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reimbursed from Hull and Machinery Insurance Proceeds</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentRedemptionPeriodThreeMember" xlink:to="us-gaap_DebtInstrumentRedemptionPeriodThreeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentRedemptionPeriodThreeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Redemption Period Three [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">SEACOR Offshore Delta (f/k/a SEACOSCO)</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LoanFacilityWithDNBBankASAMember" xlink:type="locator" xlink:label="smhi_LoanFacilityWithDNBBankASAMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_LoanFacilityWithDNBBankASAMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Related to the loan facility with DNB Bank ASA.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LoanFacilityWithDNBBankASAMember" xlink:to="smhi_LoanFacilityWithDNBBankASAMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_LoanFacilityWithDNBBankASAMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loan Facility With DNB Bank ASA</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LoanFacilityWithDNBBankASAMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Loan Facility With D N B Bank A S A [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OtherDNBCreditFacilitiesMember" xlink:type="locator" xlink:label="smhi_OtherDNBCreditFacilitiesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDNBCreditFacilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Related to the other DNB credit facilities.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OtherDNBCreditFacilitiesMember" xlink:to="smhi_OtherDNBCreditFacilitiesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDNBCreditFacilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other DNB Credit Facilities</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDNBCreditFacilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other D N B Credit Facilities [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentRiskAxis" xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentRiskAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Instrument</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentRiskAxis" xlink:to="us-gaap_DerivativeInstrumentRiskAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentRiskAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instrument Risk [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeContractTypeDomain" xlink:type="locator" xlink:label="us-gaap_DerivativeContractTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeContractTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Contract</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeContractTypeDomain" xlink:to="us-gaap_DerivativeContractTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeContractTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Contract Type [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestRateSwapMember" xlink:type="locator" xlink:label="us-gaap_InterestRateSwapMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestRateSwapMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest Rate Swap</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestRateSwapMember" xlink:to="us-gaap_InterestRateSwapMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestRateSwapMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Swap [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TaxRefundAndIndemnificationAgreementMember" xlink:type="locator" xlink:label="smhi_TaxRefundAndIndemnificationAgreementMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TaxRefundAndIndemnificationAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Tax refund and indemnification agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TaxRefundAndIndemnificationAgreementMember" xlink:to="smhi_TaxRefundAndIndemnificationAgreementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TaxRefundAndIndemnificationAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax Refund Agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TaxRefundAndIndemnificationAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Tax Refund And Indemnification Agreement [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ConvertibleSeniorNotes375PercentMember" xlink:type="locator" xlink:label="smhi_ConvertibleSeniorNotes375PercentMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotes375PercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to the 3.75% Convertible Senior Notes.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ConvertibleSeniorNotes375PercentMember" xlink:to="smhi_ConvertibleSeniorNotes375PercentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotes375PercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Senior Notes 3.75%</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotes375PercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Senior Notes375 Percent [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightAxis" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of Warrant or Right</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightAxis" xlink:to="us-gaap_ClassOfWarrantOrRightAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrant Or Right [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of Warrant or Right</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightDomain" xlink:to="us-gaap_ClassOfWarrantOrRightDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrant Or Right [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CarlyleWarrantsMember" xlink:type="locator" xlink:label="smhi_CarlyleWarrantsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarlyleWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Related to the Carlyle Warrants.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CarlyleWarrantsMember" xlink:to="smhi_CarlyleWarrantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarlyleWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Carlyle Warrants</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CarlyleWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Carlyle Warrants [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ThreePointSevenFivePercentageConvertibleNotesMember" xlink:type="locator" xlink:label="smhi_ThreePointSevenFivePercentageConvertibleNotesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ThreePointSevenFivePercentageConvertibleNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Three point seven five percentage convertible notes.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ThreePointSevenFivePercentageConvertibleNotesMember" xlink:to="smhi_ThreePointSevenFivePercentageConvertibleNotesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ThreePointSevenFivePercentageConvertibleNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Three Point Seven Five Percentage Convertible Notes</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ThreePointSevenFivePercentageConvertibleNotesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Three Point Seven Five Percentage Convertible Notes [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionByUniqueDescriptionAxis" xlink:type="locator" xlink:label="us-gaap_DebtConversionByUniqueDescriptionAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtConversionByUniqueDescriptionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Conversion Description</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionByUniqueDescriptionAxis" xlink:to="us-gaap_DebtConversionByUniqueDescriptionAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtConversionByUniqueDescriptionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion By Unique Description [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionNameDomain" xlink:type="locator" xlink:label="us-gaap_DebtConversionNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtConversionNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt Conversion, Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionNameDomain" xlink:to="us-gaap_DebtConversionNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtConversionNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion Name [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ConvertibleSeniorNotesConvertedToWarrantsMember" xlink:type="locator" xlink:label="smhi_ConvertibleSeniorNotesConvertedToWarrantsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotesConvertedToWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the conversion of convertible senior notes to warrants.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ConvertibleSeniorNotesConvertedToWarrantsMember" xlink:to="smhi_ConvertibleSeniorNotesConvertedToWarrantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotesConvertedToWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible Senior Notes Converted to Warrants</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ConvertibleSeniorNotesConvertedToWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Senior Notes Converted To Warrants [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_CounterpartyNameAxis" xlink:type="locator" xlink:label="srt_CounterpartyNameAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_CounterpartyNameAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Counterparty Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_CounterpartyNameAxis" xlink:to="srt_CounterpartyNameAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_CounterpartyNameAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Counterparty Name [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_RepurchaseAgreementCounterpartyNameDomain" xlink:type="locator" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Counterparty Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_RepurchaseAgreementCounterpartyNameDomain" xlink:to="srt_RepurchaseAgreementCounterpartyNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_RepurchaseAgreementCounterpartyNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Repurchase Agreement Counterparty Name [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CarlyleGroupMember" xlink:type="locator" xlink:label="smhi_CarlyleGroupMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarlyleGroupMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to Carlyle Group.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CarlyleGroupMember" xlink:to="smhi_CarlyleGroupMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarlyleGroupMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Carlyle Group</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CarlyleGroupMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Carlyle Group [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SeaCatCrewzerIIITermLoanFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Sea-Cat Crewzer III</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TermLoanToAcquireTwoVesselsMember" xlink:type="locator" xlink:label="smhi_TermLoanToAcquireTwoVesselsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TermLoanToAcquireTwoVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Related to a term loan to acquire two vessels.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TermLoanToAcquireTwoVesselsMember" xlink:to="smhi_TermLoanToAcquireTwoVesselsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TermLoanToAcquireTwoVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term Loan to Acquire Two Vessels</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TermLoanToAcquireTwoVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Term Loan To Acquire Two Vessels [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GuaranteeObligationsByNatureAxis" xlink:type="locator" xlink:label="us-gaap_GuaranteeObligationsByNatureAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsByNatureAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Guarantor Obligations, Nature</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GuaranteeObligationsByNatureAxis" xlink:to="us-gaap_GuaranteeObligationsByNatureAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsByNatureAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Guarantee Obligations By Nature [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GuaranteeObligationsNatureDomain" xlink:type="locator" xlink:label="us-gaap_GuaranteeObligationsNatureDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsNatureDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Guarantor Obligations, Nature</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GuaranteeObligationsNatureDomain" xlink:to="us-gaap_GuaranteeObligationsNatureDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsNatureDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Guarantee Obligations Nature [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LongtermDebtObligationMember" xlink:type="locator" xlink:label="smhi_LongtermDebtObligationMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_LongtermDebtObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Related to a long-term debt obligation.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LongtermDebtObligationMember" xlink:to="smhi_LongtermDebtObligationMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_LongtermDebtObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term Debt Obligation</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LongtermDebtObligationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Longterm Debt Obligation [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LineOfCreditFacilityAssumedAndGuaranteed_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of credit facility assumed and guaranteed</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LineOfCreditFacilityAssumedAndGuaranteed_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Assumed And Guaranteed</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityFrequencyOfPayments" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityFrequencyOfPayments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityFrequencyOfPayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit facility, frequency of payments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityFrequencyOfPayments" xlink:to="us-gaap_LineOfCreditFacilityFrequencyOfPayments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityFrequencyOfPayments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Frequency Of Payments</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityPeriodicPaymentPrincipal" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityPeriodicPaymentPrincipal" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityPeriodicPaymentPrincipal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit facility quarterly principal payments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityPeriodicPaymentPrincipal" xlink:to="us-gaap_LineOfCreditFacilityPeriodicPaymentPrincipal_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityPeriodicPaymentPrincipal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Periodic Payment Principal</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityInterestRateDuringPeriod" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit facility, interest rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod" xlink:to="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityInterestRateDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Interest Rate During Period</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityExpirationDate1" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityExpirationDate1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityExpirationDate1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit facility, maturity date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityExpirationDate1" xlink:to="us-gaap_LineOfCreditFacilityExpirationDate1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityExpirationDate1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Expiration Date1</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DebtInstrumentMaturityYear" xlink:type="locator" xlink:label="smhi_DebtInstrumentMaturityYear" />
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentMaturityYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt instrument maturity year.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DebtInstrumentMaturityYear" xlink:to="smhi_DebtInstrumentMaturityYear_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFaceAmount" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentFaceAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, face amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFaceAmount" xlink:to="us-gaap_DebtInstrumentFaceAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentFaceAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Face Amount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebtPercentageBearingFixedInterestRate" xlink:type="locator" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Term loan fixed interest percentage rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebtPercentageBearingFixedInterestRate" xlink:to="us-gaap_LongTermDebtPercentageBearingFixedInterestRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebtPercentageBearingFixedInterestRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt Percentage Bearing Fixed Interest Rate</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentMaturityYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, maturity year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentMaturityYear_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Maturity Year</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfLiftboatsReleasedFromMortgagesAndSecurityArrangements" xlink:type="locator" xlink:label="smhi_NumberOfLiftboatsReleasedFromMortgagesAndSecurityArrangements" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfLiftboatsReleasedFromMortgagesAndSecurityArrangements_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of liftboats released from mortgages and security arrangements.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfLiftboatsReleasedFromMortgagesAndSecurityArrangements" xlink:to="smhi_NumberOfLiftboatsReleasedFromMortgagesAndSecurityArrangements_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ReimbursementAmount" xlink:type="locator" xlink:label="smhi_ReimbursementAmount" />
    <link:label xml:lang="en-US" xlink:label="smhi_ReimbursementAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Reimbursement amount.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ReimbursementAmount" xlink:to="smhi_ReimbursementAmount_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCredit" xlink:type="locator" xlink:label="us-gaap_LineOfCredit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Principal outstanding under Credit Facility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCredit" xlink:to="us-gaap_LineOfCredit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_RepaymentsOfLongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Repayments of long-term debt, total</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ReimbursementAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Reimbursement amount</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ReimbursementAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Reimbursement Amount</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfLiftboatsReleasedFromMortgagesAndSecurityArrangements_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of liftboats released from mortgages and security arrangements</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfLiftboatsReleasedFromMortgagesAndSecurityArrangements_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Liftboats Released From Mortgages And Security Arrangements</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GainsLossesOnRestructuringOfDebt" xlink:type="locator" xlink:label="us-gaap_GainsLossesOnRestructuringOfDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainsLossesOnRestructuringOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain on restructuring of debt</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GainsLossesOnRestructuringOfDebt" xlink:to="us-gaap_GainsLossesOnRestructuringOfDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainsLossesOnRestructuringOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Gains Losses On Restructuring Of Debt</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_HullAndMachineryInsuranceProceeds" xlink:type="locator" xlink:label="smhi_HullAndMachineryInsuranceProceeds" />
    <link:label xml:lang="en-US" xlink:label="smhi_HullAndMachineryInsuranceProceeds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Hull and machinery insurance proceeds.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_HullAndMachineryInsuranceProceeds" xlink:to="smhi_HullAndMachineryInsuranceProceeds_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtCurrent" xlink:type="locator" xlink:label="us-gaap_DebtCurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Current Liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtCurrent" xlink:to="us-gaap_DebtCurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Current</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentFeeAmount" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentFeeAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentFeeAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Transaction Fees</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentFeeAmount" xlink:to="us-gaap_DebtInstrumentFeeAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentFeeAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Fee Amount</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_RepaymentsOfLongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedTerseLabel">Cash Paid</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_HullAndMachineryInsuranceProceeds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Hull and Machinery Insurance Proceeds</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_HullAndMachineryInsuranceProceeds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Hull And Machinery Insurance Proceeds</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_TroubledDebtRestructuringDebtorCurrentPeriodGainLossOnRestructuringNetOfTax" xlink:type="locator" xlink:label="us-gaap_TroubledDebtRestructuringDebtorCurrentPeriodGainLossOnRestructuringNetOfTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TroubledDebtRestructuringDebtorCurrentPeriodGainLossOnRestructuringNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain on Troubled Debt Restructuring</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_TroubledDebtRestructuringDebtorCurrentPeriodGainLossOnRestructuringNetOfTax" xlink:to="us-gaap_TroubledDebtRestructuringDebtorCurrentPeriodGainLossOnRestructuringNetOfTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_TroubledDebtRestructuringDebtorCurrentPeriodGainLossOnRestructuringNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Troubled Debt Restructuring Debtor Current Period Gain Loss On Restructuring Net Of Tax</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfBasicEarningsPerShare" xlink:type="locator" xlink:label="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfBasicEarningsPerShare" />
    <link:label xml:lang="en-US" xlink:label="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfBasicEarningsPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Troubled debt restructuring debtor current period increase decrease of basic earnings per share.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfBasicEarningsPerShare" xlink:to="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfBasicEarningsPerShare_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfDilutedEarningsPerShare" xlink:type="locator" xlink:label="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfDilutedEarningsPerShare" />
    <link:label xml:lang="en-US" xlink:label="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfDilutedEarningsPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Troubled debt restructuring debtor current period increase decrease of diluted earnings per share.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfDilutedEarningsPerShare" xlink:to="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfDilutedEarningsPerShare_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfBasicEarningsPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain on troubled debt restructuring, increase of basic earnings per share</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfBasicEarningsPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Troubled Debt Restructuring Debtor Current Period Increase Decrease Of Basic Earnings Per Share</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfDilutedEarningsPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain on troubled debt restructuring, increase of diluted earnings per share</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TroubledDebtRestructuringDebtorCurrentPeriodIncreaseDecreaseOfDilutedEarningsPerShare_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Troubled Debt Restructuring Debtor Current Period Increase Decrease Of Diluted Earnings Per Share</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DebtInstrumentPercentageOfFinancingOnTotalPurchasePrice" xlink:type="locator" xlink:label="smhi_DebtInstrumentPercentageOfFinancingOnTotalPurchasePrice" />
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentPercentageOfFinancingOnTotalPurchasePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt instrument, percentage of financing on total purchase price.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DebtInstrumentPercentageOfFinancingOnTotalPurchasePrice" xlink:to="smhi_DebtInstrumentPercentageOfFinancingOnTotalPurchasePrice_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, interest rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateStatedPercentage" xlink:to="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentInterestRateStatedPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Interest Rate Stated Percentage</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentPercentageOfFinancingOnTotalPurchasePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of amount of loan financed</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentPercentageOfFinancingOnTotalPurchasePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Percentage Of Financing On Total Purchase Price</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentTerm" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentTerm" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, term of delivery</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentTerm" xlink:to="us-gaap_DebtInstrumentTerm_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Term</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DebtInstrumentExtendedMaturityDate" xlink:type="locator" xlink:label="smhi_DebtInstrumentExtendedMaturityDate" />
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentExtendedMaturityDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt instrument extended maturity date.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DebtInstrumentExtendedMaturityDate" xlink:to="smhi_DebtInstrumentExtendedMaturityDate_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ApplicationFeePaidInConjunctionWithAmendmentAndAmortizedOverCreditFacilityTerm" xlink:type="locator" xlink:label="smhi_ApplicationFeePaidInConjunctionWithAmendmentAndAmortizedOverCreditFacilityTerm" />
    <link:label xml:lang="en-US" xlink:label="smhi_ApplicationFeePaidInConjunctionWithAmendmentAndAmortizedOverCreditFacilityTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Application fee paid in conjunction with amendment and amortized over credit facility term.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ApplicationFeePaidInConjunctionWithAmendmentAndAmortizedOverCreditFacilityTerm" xlink:to="smhi_ApplicationFeePaidInConjunctionWithAmendmentAndAmortizedOverCreditFacilityTerm_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:type="locator" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Line of credit facility, maximum borrowing capacity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity" xlink:to="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LineOfCreditFacilityMaximumBorrowingCapacity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Line Of Credit Facility Maximum Borrowing Capacity</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentExtendedMaturityDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, extended maturity date</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentExtendedMaturityDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Extended Maturity Date</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ApplicationFeePaidInConjunctionWithAmendmentAndAmortizedOverCreditFacilityTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Application fee paid in conjunction with amendment and amortized over credit facility term</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ApplicationFeePaidInConjunctionWithAmendmentAndAmortizedOverCreditFacilityTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Application Fee Paid In Conjunction With Amendment And Amortized Over Credit Facility Term</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromLinesOfCredit" xlink:type="locator" xlink:label="us-gaap_ProceedsFromLinesOfCredit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from lines of credit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromLinesOfCredit" xlink:to="us-gaap_ProceedsFromLinesOfCredit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromLinesOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Lines Of Credit</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, increase (decrease), net,</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet" xlink:to="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentIncreaseDecreaseForPeriodNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Increase Decrease For Period Net</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PurchasePricePayableForEquityMethodInvestmentInYearOne" xlink:type="locator" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearOne" />
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase price payable for equity method investment in year one.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PurchasePricePayableForEquityMethodInvestmentInYearOne" xlink:to="smhi_PurchasePricePayableForEquityMethodInvestmentInYearOne_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PurchasePricePayableForEquityMethodInvestmentInYearTwo" xlink:type="locator" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearTwo" />
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase price payable for equity method investment in year two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PurchasePricePayableForEquityMethodInvestmentInYearTwo" xlink:to="smhi_PurchasePricePayableForEquityMethodInvestmentInYearTwo_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PurchasePricePayableForEquityMethodInvestmentInYearThree" xlink:type="locator" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearThree" />
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase price payable for equity method investment in year three.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PurchasePricePayableForEquityMethodInvestmentInYearThree" xlink:to="smhi_PurchasePricePayableForEquityMethodInvestmentInYearThree_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PurchasePricePayableForEquityMethodInvestmentInYearFour" xlink:type="locator" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearFour" />
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Purchase price payable for equity method investment in year four.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PurchasePricePayableForEquityMethodInvestmentInYearFour" xlink:to="smhi_PurchasePricePayableForEquityMethodInvestmentInYearFour_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearOne" xlink:type="locator" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearOne" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of purchase price fixed accrued interest rate for equity method investment in year one.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearOne" xlink:to="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearOne_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearTwo" xlink:type="locator" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearTwo" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of purchase price fixed accrued interest rate for equity method investment in year two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearTwo" xlink:to="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearTwo_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearThree" xlink:type="locator" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearThree" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of purchase price fixed accrued interest rate for equity method investment in year three.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearThree" xlink:to="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearThree_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearFour" xlink:type="locator" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearFour" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of purchase price fixed accrued interest rate for equity method investment in year four.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearFour" xlink:to="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearFour_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentPurchasePriceAmortizationPeriod" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentPurchasePriceAmortizationPeriod" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentPurchasePriceAmortizationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity method investment purchase price amortization period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentPurchasePriceAmortizationPeriod" xlink:to="smhi_EquityMethodInvestmentPurchasePriceAmortizationPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price payable for equity method investment in first year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Purchase Price Payable For Equity Method Investment In Year One</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price payable for equity method investment in second year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Purchase Price Payable For Equity Method Investment In Year Two</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Purchase price payable for equity method investment in third year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Purchase Price Payable For Equity Method Investment In Year Three</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price payable for equity method investment in fourth year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PurchasePricePayableForEquityMethodInvestmentInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Purchase Price Payable For Equity Method Investment In Year Four</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price fixed accrued interest rate in first year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearOne_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Purchase Price Fixed Accrued Interest Rate For Equity Method Investment In Year One</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price fixed accrued interest rate in second year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearTwo_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Purchase Price Fixed Accrued Interest Rate For Equity Method Investment In Year Two</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price fixed accrued interest rate in third year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearThree_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Purchase Price Fixed Accrued Interest Rate For Equity Method Investment In Year Three</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Purchase price fixed accrued interest rate in fourth year</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfPurchasePriceFixedAccruedInterestRateForEquityMethodInvestmentInYearFour_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Purchase Price Fixed Accrued Interest Rate For Equity Method Investment In Year Four</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentPurchasePriceAmortizationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity method investment, amortization of purchase price</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentPurchasePriceAmortizationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Purchase Price Amortization Period</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DebtInstrumentMaturityPeriod" xlink:type="locator" xlink:label="smhi_DebtInstrumentMaturityPeriod" />
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentMaturityPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt instrument, maturity period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DebtInstrumentMaturityPeriod" xlink:to="smhi_DebtInstrumentMaturityPeriod_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, interest rate, effective percentage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateEffectivePercentage" xlink:to="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentInterestRateEffectivePercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Interest Rate Effective Percentage</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentMaturityPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, maturity period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtInstrumentMaturityPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Maturity Period</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RepaymentsOfLinesOfCredit" xlink:type="locator" xlink:label="us-gaap_RepaymentsOfLinesOfCredit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RepaymentsOfLinesOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Repayments of lines of credit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RepaymentsOfLinesOfCredit" xlink:to="us-gaap_RepaymentsOfLinesOfCredit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RepaymentsOfLinesOfCredit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Repayments Of Lines Of Credit</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermDebt" xlink:type="locator" xlink:label="us-gaap_LongTermDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term debt, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermDebt" xlink:to="us-gaap_LongTermDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Debt</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestPayableCurrentAndNoncurrent" xlink:type="locator" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest payable</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestPayableCurrentAndNoncurrent" xlink:to="us-gaap_InterestPayableCurrentAndNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestPayableCurrentAndNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Payable Current And Noncurrent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentPeriodicPaymentPrincipal" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentPrincipal" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentPrincipal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, periodic payment, principal</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentPeriodicPaymentPrincipal" xlink:to="us-gaap_DebtInstrumentPeriodicPaymentPrincipal_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentPeriodicPaymentPrincipal_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Periodic Payment Principal</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainsLossesOnExtinguishmentOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Gain on troubled debt restructuring</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNotionalAmount" xlink:type="locator" xlink:label="us-gaap_DerivativeNotionalAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeNotionalAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative, notional amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeNotionalAmount" xlink:to="us-gaap_DerivativeNotionalAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeNotionalAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Notional Amount</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfAdditionalVesselsOwned" xlink:type="locator" xlink:label="smhi_NumberOfAdditionalVesselsOwned" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfAdditionalVesselsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of additional vessels owned.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfAdditionalVesselsOwned" xlink:to="smhi_NumberOfAdditionalVesselsOwned_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfAdditionalVesselsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of additional vessels owned</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfAdditionalVesselsOwned_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Additional Vessels Owned</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EstimatedCashOrCashEquivalentsTaxRefundsReceivable" xlink:type="locator" xlink:label="smhi_EstimatedCashOrCashEquivalentsTaxRefundsReceivable" />
    <link:label xml:lang="en-US" xlink:label="smhi_EstimatedCashOrCashEquivalentsTaxRefundsReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Estimated cash or cash equivalents tax refunds receivable.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EstimatedCashOrCashEquivalentsTaxRefundsReceivable" xlink:to="smhi_EstimatedCashOrCashEquivalentsTaxRefundsReceivable_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EstimatedCashOrCashEquivalentsTaxRefundsReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated tax refund receivable</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EstimatedCashOrCashEquivalentsTaxRefundsReceivable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Estimated Cash Or Cash Equivalents Tax Refunds Receivable</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConvertibleDebt" xlink:type="locator" xlink:label="us-gaap_ConvertibleDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConvertibleDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Convertible debt, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConvertibleDebt" xlink:to="us-gaap_ConvertibleDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConvertibleDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Convertible Debt</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionRatio1" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentConvertibleConversionRatio1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentConvertibleConversionRatio1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, convertible, conversion ratio</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentConvertibleConversionRatio1" xlink:to="us-gaap_DebtInstrumentConvertibleConversionRatio1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentConvertibleConversionRatio1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Convertible Conversion Ratio1</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of warrant or right, exercise price of warrants or rights</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1" xlink:to="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrant Or Right Exercise Price Of Warrants Or Rights1</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability" xlink:type="locator" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Embedded derivative, fair value of embedded derivative liability</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability" xlink:to="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Embedded Derivative Fair Value Of Embedded Derivative Liability</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionOriginalDebtAmount1" xlink:type="locator" xlink:label="us-gaap_DebtConversionOriginalDebtAmount1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtConversionOriginalDebtAmount1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt conversion, original debt, amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionOriginalDebtAmount1" xlink:to="us-gaap_DebtConversionOriginalDebtAmount1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtConversionOriginalDebtAmount1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion Original Debt Amount1</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:type="locator" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt conversion, converted instrument, shares issued</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtConversionConvertedInstrumentSharesIssued1" xlink:to="us-gaap_DebtConversionConvertedInstrumentSharesIssued1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtConversionConvertedInstrumentSharesIssued1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Conversion Converted Instrument Shares Issued1</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, convertible, conversion price</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentConvertibleConversionPrice1" xlink:to="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentConvertibleConversionPrice1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Convertible Conversion Price1</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_WarrantsAndRightsOutstandingTerm" xlink:type="locator" xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants and rights outstanding, term</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_WarrantsAndRightsOutstandingTerm" xlink:to="us-gaap_WarrantsAndRightsOutstandingTerm_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_WarrantsAndRightsOutstandingTerm_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Warrants And Rights Outstanding Term</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfDebt" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from issuance of debt</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfDebt" xlink:to="us-gaap_ProceedsFromIssuanceOfDebt_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIssuanceOfDebt_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Issuance Of Debt</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFinanceCostsGross" xlink:type="locator" xlink:label="us-gaap_DeferredFinanceCostsGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredFinanceCostsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt issuance costs, gross</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFinanceCostsGross" xlink:to="us-gaap_DeferredFinanceCostsGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredFinanceCostsGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Finance Costs Gross</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ClaimsRecoverableUnderBorrowingsPercentageOfObligationsOutstanding" xlink:type="locator" xlink:label="smhi_ClaimsRecoverableUnderBorrowingsPercentageOfObligationsOutstanding" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClaimsRecoverableUnderBorrowingsPercentageOfObligationsOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Claims recoverable under borrowings percentage f obligations outstanding.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ClaimsRecoverableUnderBorrowingsPercentageOfObligationsOutstanding" xlink:to="smhi_ClaimsRecoverableUnderBorrowingsPercentageOfObligationsOutstanding_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ClaimsRecoverableAmountUnderBorrowings" xlink:type="locator" xlink:label="smhi_ClaimsRecoverableAmountUnderBorrowings" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClaimsRecoverableAmountUnderBorrowings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Claims recoverable amount under borrowings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ClaimsRecoverableAmountUnderBorrowings" xlink:to="smhi_ClaimsRecoverableAmountUnderBorrowings_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClaimsRecoverableAmountUnderBorrowings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Claims recoverable amount under borrowings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClaimsRecoverableAmountUnderBorrowings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Claims Recoverable Amount Under Borrowings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClaimsRecoverableUnderBorrowingsPercentageOfObligationsOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Claims recoverable under borrowings percentage of obligations outstanding</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClaimsRecoverableUnderBorrowingsPercentageOfObligationsOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Claims Recoverable Under Borrowings Percentage Of Obligations Outstanding</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LettersOfCreditOutstandingAmount" xlink:type="locator" xlink:label="us-gaap_LettersOfCreditOutstandingAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LettersOfCreditOutstandingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Letters of credit outstanding, amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LettersOfCreditOutstandingAmount" xlink:to="us-gaap_LettersOfCreditOutstandingAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LettersOfCreditOutstandingAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Letters Of Credit Outstanding Amount</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InterestReceivedOnCashRefunds" xlink:type="locator" xlink:label="smhi_InterestReceivedOnCashRefunds" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestReceivedOnCashRefunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest received on cash refunds.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InterestReceivedOnCashRefunds" xlink:to="smhi_InterestReceivedOnCashRefunds_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_IncomeTaxesLineItems" xlink:type="locator" xlink:label="smhi_IncomeTaxesLineItems" />
    <link:label xml:lang="en-US" xlink:label="smhi_IncomeTaxesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Income Taxes.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_IncomeTaxesLineItems" xlink:to="smhi_IncomeTaxesLineItems_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_IncomeTaxesTable" xlink:type="locator" xlink:label="smhi_IncomeTaxesTable" />
    <link:label xml:lang="en-US" xlink:label="smhi_IncomeTaxesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Income taxes.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_IncomeTaxesTable" xlink:to="smhi_IncomeTaxesTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_IncomeTaxesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Taxes [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_IncomeTaxesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Taxes [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_IncomeTaxesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Taxes [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_IncomeTaxesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Taxes [Line Items]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIncomeTaxRefunds" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIncomeTaxRefunds" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIncomeTaxRefunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax refunds</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIncomeTaxRefunds" xlink:to="us-gaap_ProceedsFromIncomeTaxRefunds_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIncomeTaxRefunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Income Tax Refunds</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestReceivedOnCashRefunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest received on cash refunds</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestReceivedOnCashRefunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Received On Cash Refunds</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfNetOperatingLossesFacilitateTaxSavings" xlink:type="locator" xlink:label="smhi_PercentageOfNetOperatingLossesFacilitateTaxSavings" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfNetOperatingLossesFacilitateTaxSavings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of net operating losses facilitate tax savings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfNetOperatingLossesFacilitateTaxSavings" xlink:to="smhi_PercentageOfNetOperatingLossesFacilitateTaxSavings_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TransactionFee" xlink:type="locator" xlink:label="smhi_TransactionFee" />
    <link:label xml:lang="en-US" xlink:label="smhi_TransactionFee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Transaction fee.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TransactionFee" xlink:to="smhi_TransactionFee_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CashTaxRefundsWithoutRestrictionsToUse" xlink:type="locator" xlink:label="smhi_CashTaxRefundsWithoutRestrictionsToUse" />
    <link:label xml:lang="en-US" xlink:label="smhi_CashTaxRefundsWithoutRestrictionsToUse_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash tax refunds without restrictions to use.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CashTaxRefundsWithoutRestrictionsToUse" xlink:to="smhi_CashTaxRefundsWithoutRestrictionsToUse_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CashTaxRefundsWithRestrictionsToUse" xlink:type="locator" xlink:label="smhi_CashTaxRefundsWithRestrictionsToUse" />
    <link:label xml:lang="en-US" xlink:label="smhi_CashTaxRefundsWithRestrictionsToUse_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cash tax refunds with restrictions to use.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CashTaxRefundsWithRestrictionsToUse" xlink:to="smhi_CashTaxRefundsWithRestrictionsToUse_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfNetOperatingLossesFacilitateTaxSavings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of net operating losses facilitate tax savings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfNetOperatingLossesFacilitateTaxSavings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Net Operating Losses Facilitate Tax Savings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TransactionFee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transaction fee</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TransactionFee_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Transaction Fee</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CashTaxRefundsWithoutRestrictionsToUse_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash tax refunds without restrict to use</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CashTaxRefundsWithoutRestrictionsToUse_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash Tax Refunds Without Restrictions To Use</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CashTaxRefundsWithRestrictionsToUse_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash tax refunds with restrict to use</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CashTaxRefundsWithRestrictionsToUse_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash Tax Refunds With Restrictions To Use</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income tax benefit and equity in earnings (losses)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationEquityInEarningsLossesOfUnconsolidatedSubsidiary_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Equity In Earnings Losses Of Unconsolidated Subsidiary</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityAxis" xlink:type="locator" xlink:label="us-gaap_IncomeTaxAuthorityAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxAuthorityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Tax Authority</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxAuthorityAxis" xlink:to="us-gaap_IncomeTaxAuthorityAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxAuthorityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Authority [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxAuthorityDomain" xlink:type="locator" xlink:label="us-gaap_IncomeTaxAuthorityDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxAuthorityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Tax Authority</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxAuthorityDomain" xlink:to="us-gaap_IncomeTaxAuthorityDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxAuthorityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Authority [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DomesticCountryMember" xlink:type="locator" xlink:label="us-gaap_DomesticCountryMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DomesticCountryMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">United States</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DomesticCountryMember" xlink:to="us-gaap_DomesticCountryMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DomesticCountryMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Domestic Country [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignCountryMember" xlink:type="locator" xlink:label="us-gaap_ForeignCountryMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignCountryMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignCountryMember" xlink:to="us-gaap_ForeignCountryMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignCountryMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Country [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EliminationsMember" xlink:type="locator" xlink:label="smhi_EliminationsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_EliminationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information about Eliminations.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EliminationsMember" xlink:to="smhi_EliminationsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EliminationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Eliminations</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EliminationsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Eliminations [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeLossFromContinuingOperationsBeforeIncomeTaxesMinorityInterestAndIncomeLossFromEquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income before income tax expense (benefit) and equity in earnings of 50% or less owned companies</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentFederalTaxExpenseBenefit" xlink:type="locator" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Federal, current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentFederalTaxExpenseBenefit" xlink:to="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CurrentFederalTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Current Federal Tax Expense Benefit</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:type="locator" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State, current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentStateAndLocalTaxExpenseBenefit" xlink:to="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CurrentStateAndLocalTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Current State And Local Tax Expense Benefit</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CurrentForeignTaxExpenseBenefit" xlink:type="locator" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign, current</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CurrentForeignTaxExpenseBenefit" xlink:to="us-gaap_CurrentForeignTaxExpenseBenefit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CurrentForeignTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Current Foreign Tax Expense Benefit</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_CurrentIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Current income tax expense</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:type="locator" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Federal, deferred</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredFederalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredFederalIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Federal Income Tax Expense Benefit</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:type="locator" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State, deferred</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredStateAndLocalIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred State And Local Income Tax Expense Benefit</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:type="locator" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign, deferred</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredForeignIncomeTaxExpenseBenefit" xlink:to="us-gaap_DeferredForeignIncomeTaxExpenseBenefit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredForeignIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Foreign Income Tax Expense Benefit</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Deferred income tax benefit</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_IncreaseDecreaseInTransitionTaxLiability" xlink:type="locator" xlink:label="smhi_IncreaseDecreaseInTransitionTaxLiability" />
    <link:label xml:lang="en-US" xlink:label="smhi_IncreaseDecreaseInTransitionTaxLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The amount of increase (decrease) in transition tax liability.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_IncreaseDecreaseInTransitionTaxLiability" xlink:to="smhi_IncreaseDecreaseInTransitionTaxLiability_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxReconciliationTaxCreditsForeign" xlink:type="locator" xlink:label="us-gaap_IncomeTaxReconciliationTaxCreditsForeign" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxReconciliationTaxCreditsForeign_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign tax credits</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxReconciliationTaxCreditsForeign" xlink:to="us-gaap_IncomeTaxReconciliationTaxCreditsForeign_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxReconciliationTaxCreditsForeign_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Reconciliation Tax Credits Foreign</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority" xlink:type="locator" xlink:label="us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Expected tax refund</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority" xlink:to="us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeTaxExaminationLiabilityRefundAdjustmentFromSettlementWithTaxingAuthority_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Tax Examination Liability Refund Adjustment From Settlement With Taxing Authority</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_IncreaseDecreaseInTransitionTaxLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Increase (decrease) in transition tax liability</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_IncreaseDecreaseInTransitionTaxLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Increase Decrease In Transition Tax Liability</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EffectiveIncomeTaxRateReconciliationJVEquityEarnings" xlink:type="locator" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationJVEquityEarnings" />
    <link:label xml:lang="en-US" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationJVEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Effective income tax Rate reconciliation JV equity earnings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EffectiveIncomeTaxRateReconciliationJVEquityEarnings" xlink:to="smhi_EffectiveIncomeTaxRateReconciliationJVEquityEarnings_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EffectiveIncomeTaxRateReconciliationReturnToProvision" xlink:type="locator" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationReturnToProvision" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_EffectiveIncomeTaxRateReconciliationShareAwardPlans" xlink:type="locator" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationShareAwardPlans" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperationsTaxRateReconciliationAbstract" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Statutory rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation At Federal Statutory Income Tax Rate</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exclusion of foreign subsidiaries with current year losses and withholding tax</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationTaxExemptIncome_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Tax Exempt Income</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">U.S. federal income tax law changes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationChangeInEnactedTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Change In Enacted Tax Rate</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-Deductible Expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationNondeductibleExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Nondeductible Expense</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationJVEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">JV equity earnings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationJVEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation J V Equity Earnings</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Noncontrolling interests</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationMinorityInterestIncomeExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Minority Interest Income Expense</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationReturnToProvision_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Return to provision</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationReturnToProvision_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Return To Provision</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">State Taxes</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes" xlink:to="us-gaap_EffectiveIncomeTaxRateReconciliationStateAndLocalIncomeTaxes_lbl" />
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    <link:label xml:lang="en-US" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationSubpartFIncome_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subpart F Income</link:label>
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    <link:label xml:lang="en-US" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationShareAwardPlans_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share Award Plans</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EffectiveIncomeTaxRateReconciliationShareAwardPlans_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Share Award Plans</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationOtherAdjustments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Effective Income Tax Rate Reconciliation Other Adjustments</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EffectiveIncomeTaxRateContinuingOperations" xlink:type="locator" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateContinuingOperations_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Effective income tax rate reconciliation, percent, total</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_EffectiveIncomeTaxRateReconciliationAtFederalStatutoryIncomeTaxRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Effective income tax rate reconciliation, at federal statutory income tax rate, percent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:type="locator" xlink:label="us-gaap_DeferredTaxLiabilitiesNetAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxLiabilitiesNetAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred tax liabilities:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxLiabilitiesNetAbstract" xlink:to="us-gaap_DeferredTaxLiabilitiesNetAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxLiabilitiesNetAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities Net [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" xlink:type="locator" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Property and equipment</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxLiabilitiesPropertyPlantAndEquipment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities Property Plant And Equipment</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxLiabilitiesInvestmentInNoncontrolledAffiliates" xlink:type="locator" xlink:label="us-gaap_DeferredTaxLiabilitiesInvestmentInNoncontrolledAffiliates" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxLiabilitiesOther_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxLiabilitiesOther_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Liabilities Other</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total deferred tax liabilities</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxAssetsNetAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deferred tax assets:</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxAssetsNetAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets Net [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsOperatingLossCarryforwards" />
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxAssetsOther_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxAssetsValuationAllowance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets Valuation Allowance</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsNet" xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Total deferred tax assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsNet" xlink:to="us-gaap_DeferredTaxAssetsNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxAssetsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets Net</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:type="locator" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Net deferred tax liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DeferredTaxAssetsLiabilitiesNet" xlink:to="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DeferredTaxAssetsLiabilitiesNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deferred Tax Assets Liabilities Net</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OperatingLossCarryforwardsExpirationPeriod" xlink:type="locator" xlink:label="smhi_OperatingLossCarryforwardsExpirationPeriod" />
    <link:label xml:lang="en-US" xlink:label="smhi_OperatingLossCarryforwardsExpirationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents expiration period of operating loss carryforwards.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OperatingLossCarryforwardsExpirationPeriod" xlink:to="smhi_OperatingLossCarryforwardsExpirationPeriod_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InterestExpenseSuspendedDeductible" xlink:type="locator" xlink:label="smhi_InterestExpenseSuspendedDeductible" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspendedDeductible_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest expense suspended deductible.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InterestExpenseSuspendedDeductible" xlink:to="smhi_InterestExpenseSuspendedDeductible_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InterestExpenseSuspended" xlink:type="locator" xlink:label="smhi_InterestExpenseSuspended" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspended_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest expense suspended.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InterestExpenseSuspended" xlink:to="smhi_InterestExpenseSuspended_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InterestExpenseSuspendedLimitationPercentage" xlink:type="locator" xlink:label="smhi_InterestExpenseSuspendedLimitationPercentage" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspendedLimitationPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest expense suspended limitation percentage.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InterestExpenseSuspendedLimitationPercentage" xlink:to="smhi_InterestExpenseSuspendedLimitationPercentage_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OperatingLossCarryforwardsPercentageOfTaxableIncomeUtilizationLimitation" xlink:type="locator" xlink:label="smhi_OperatingLossCarryforwardsPercentageOfTaxableIncomeUtilizationLimitation" />
    <link:label xml:lang="en-US" xlink:label="smhi_OperatingLossCarryforwardsPercentageOfTaxableIncomeUtilizationLimitation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the percentage of taxable income as a limitation to future utilization of net operating loss.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OperatingLossCarryforwardsPercentageOfTaxableIncomeUtilizationLimitation" xlink:to="smhi_OperatingLossCarryforwardsPercentageOfTaxableIncomeUtilizationLimitation_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InterestExpenseCarryforward" xlink:type="locator" xlink:label="smhi_InterestExpenseCarryforward" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseCarryforward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest expense carryforward.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InterestExpenseCarryforward" xlink:to="smhi_InterestExpenseCarryforward_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspended_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest expense suspended</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspended_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense Suspended</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspendedDeductible_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Suspended interest deductible</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspendedDeductible_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense Suspended Deductible</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseCarryforward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest expense carryforward</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseCarryforward_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense Carryforward</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspendedLimitationPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest expense suspended, limitation percentage</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestExpenseSuspendedLimitationPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense Suspended Limitation Percentage</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OperatingLossCarryforwardsPercentageOfTaxableIncomeUtilizationLimitation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforwards, percentage of taxable income, utilization limitation</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OperatingLossCarryforwardsPercentageOfTaxableIncomeUtilizationLimitation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards Percentage Of Taxable Income Utilization Limitation</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwards" xlink:type="locator" xlink:label="us-gaap_OperatingLossCarryforwards" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLossCarryforwards_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforwards, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLossCarryforwards" xlink:to="us-gaap_OperatingLossCarryforwards_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLossCarryforwards_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OperatingLossCarryforwardsExpirationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforwards, expiration period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OperatingLossCarryforwardsExpirationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards Expiration Period</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OperatingLossCarryforwardsValuationAllowance" xlink:type="locator" xlink:label="us-gaap_OperatingLossCarryforwardsValuationAllowance" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLossCarryforwardsValuationAllowance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss carryforwards, valuation allowance, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OperatingLossCarryforwardsValuationAllowance" xlink:to="us-gaap_OperatingLossCarryforwardsValuationAllowance_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingLossCarryforwardsValuationAllowance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Operating Loss Carryforwards Valuation Allowance</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeTable" xlink:type="locator" xlink:label="us-gaap_DerivativeTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeTable" xlink:to="us-gaap_DerivativeTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationAxis" xlink:type="locator" xlink:label="us-gaap_HedgingDesignationAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_HedgingDesignationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Hedging Designation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_HedgingDesignationAxis" xlink:to="us-gaap_HedgingDesignationAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_HedgingDesignationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Hedging Designation [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingDesignationDomain" xlink:type="locator" xlink:label="us-gaap_HedgingDesignationDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_HedgingDesignationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Hedging Designation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_HedgingDesignationDomain" xlink:to="us-gaap_HedgingDesignationDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_HedgingDesignationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Hedging Designation [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DesignatedAsHedgingInstrumentMember" xlink:type="locator" xlink:label="us-gaap_DesignatedAsHedgingInstrumentMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DesignatedAsHedgingInstrumentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Designated as Hedging Instrument</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DesignatedAsHedgingInstrumentMember" xlink:to="us-gaap_DesignatedAsHedgingInstrumentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DesignatedAsHedgingInstrumentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Designated As Hedging Instrument [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NondesignatedMember" xlink:type="locator" xlink:label="us-gaap_NondesignatedMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NondesignatedMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Not Designated as Hedging Instrument</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NondesignatedMember" xlink:to="us-gaap_NondesignatedMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NondesignatedMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Nondesignated [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignExchangeForwardMember" xlink:type="locator" xlink:label="us-gaap_ForeignExchangeForwardMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignExchangeForwardMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Forward Exchange Contract</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignExchangeForwardMember" xlink:to="us-gaap_ForeignExchangeForwardMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignExchangeForwardMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Exchange Forward [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Hedging Relationship</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis" xlink:to="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentsGainLossByHedgingRelationshipAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments Gain Loss By Hedging Relationship [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_HedgingRelationshipDomain" xlink:type="locator" xlink:label="us-gaap_HedgingRelationshipDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_HedgingRelationshipDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Hedging Relationship</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_HedgingRelationshipDomain" xlink:to="us-gaap_HedgingRelationshipDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_HedgingRelationshipDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Hedging Relationship [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CashFlowHedgingMember" xlink:type="locator" xlink:label="us-gaap_CashFlowHedgingMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CashFlowHedgingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cash Flow Hedging</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CashFlowHedgingMember" xlink:to="us-gaap_CashFlowHedgingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CashFlowHedgingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cash Flow Hedging [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLineItems" xlink:type="locator" xlink:label="us-gaap_DerivativeLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeLineItems" xlink:to="us-gaap_DerivativeLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative [Line Items]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeAssets" xlink:type="locator" xlink:label="us-gaap_DerivativeAssets" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative instruments (included in other receivables)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeAssets" xlink:to="us-gaap_DerivativeAssets_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Assets</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeLiabilities" xlink:type="locator" xlink:label="us-gaap_DerivativeLiabilities" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Liability</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeLiabilities" xlink:to="us-gaap_DerivativeLiabilities_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Liabilities</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmbeddedDerivativeFairValueOfEmbeddedDerivativeLiability_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Conversion option liability on Convertible Senior Notes</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByLiabilityClassAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByLiabilityClassAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueByLiabilityClassAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liability Class</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueByLiabilityClassAxis" xlink:to="us-gaap_FairValueByLiabilityClassAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueByLiabilityClassAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value By Liability Class [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:type="locator" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value by Liability Class</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain" xlink:to="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueLiabilitiesMeasuredOnRecurringBasisUnobservableInputReconciliationByLiabilityClassDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Liabilities Measured On Recurring Basis Unobservable Input Reconciliation By Liability Class [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember" xlink:type="locator" xlink:label="us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative Liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember" xlink:to="us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeFinancialInstrumentsLiabilitiesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Financial Instruments Liabilities [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueHedgingMember" xlink:type="locator" xlink:label="us-gaap_FairValueHedgingMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueHedgingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Hedging</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueHedgingMember" xlink:to="us-gaap_FairValueHedgingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueHedgingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Hedging [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InterestRateSwapAgreementThreePointThreeTwoPercentMember" xlink:type="locator" xlink:label="smhi_InterestRateSwapAgreementThreePointThreeTwoPercentMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestRateSwapAgreementThreePointThreeTwoPercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest rate swap agreement three point one nine five percent.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InterestRateSwapAgreementThreePointThreeTwoPercentMember" xlink:to="smhi_InterestRateSwapAgreementThreePointThreeTwoPercentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestRateSwapAgreementThreePointThreeTwoPercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">3.32% Interest Rate Swap Agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestRateSwapAgreementThreePointThreeTwoPercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Swap Agreement Three Point Three Two Percent [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InterestRateSwapAgreementThreePointOneNineFivePercentMember" xlink:type="locator" xlink:label="smhi_InterestRateSwapAgreementThreePointOneNineFivePercentMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestRateSwapAgreementThreePointOneNineFivePercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest rate swap agreement three point one nine five percent.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InterestRateSwapAgreementThreePointOneNineFivePercentMember" xlink:to="smhi_InterestRateSwapAgreementThreePointOneNineFivePercentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestRateSwapAgreementThreePointOneNineFivePercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">3.195% Interest Rate Swap Agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestRateSwapAgreementThreePointOneNineFivePercentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Rate Swap Agreement Three Point One Nine Five Percent [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACOR88888Member" xlink:type="locator" xlink:label="smhi_SEACOR88888Member" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOR88888Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">SEACOR 88888.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACOR88888Member" xlink:to="smhi_SEACOR88888Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOR88888Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR 88/888</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACOR88888Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R88888 [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_WindcatWorkboatsLtdMember" xlink:type="locator" xlink:label="smhi_WindcatWorkboatsLtdMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsLtdMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information about Windcat Workboats Ltd.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_WindcatWorkboatsLtdMember" xlink:to="smhi_WindcatWorkboatsLtdMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsLtdMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Windcat Workboats Holdings Ltd</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_WindcatWorkboatsLtdMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Windcat Workboats Ltd [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1" xlink:type="locator" xlink:label="us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Recognized gain (loss) on hedged item in fair value hedge</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1" xlink:to="us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ChangeInUnrealizedGainLossOnHedgedItemInFairValueHedge1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Change In Unrealized Gain Loss On Hedged Item In Fair Value Hedge1</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DerivativesNotionalAmount" xlink:type="locator" xlink:label="smhi_DerivativesNotionalAmount" />
    <link:label xml:lang="en-US" xlink:label="smhi_DerivativesNotionalAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Derivatives notional amount.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DerivativesNotionalAmount" xlink:to="smhi_DerivativesNotionalAmount_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFixedInterestRate" xlink:type="locator" xlink:label="us-gaap_DerivativeFixedInterestRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeFixedInterestRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative, fixed interest rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeFixedInterestRate" xlink:to="us-gaap_DerivativeFixedInterestRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeFixedInterestRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Fixed Interest Rate</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DerivativesNotionalAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative, notional amount</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DerivativesNotionalAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivatives Notional Amount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeNumberOfInstrumentsHeld" xlink:type="locator" xlink:label="us-gaap_DerivativeNumberOfInstrumentsHeld" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeNumberOfInstrumentsHeld_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Derivative, number of instruments held, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeNumberOfInstrumentsHeld" xlink:to="us-gaap_DerivativeNumberOfInstrumentsHeld_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeNumberOfInstrumentsHeld_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Number Of Instruments Held</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeFairValueOfDerivativeNet" xlink:type="locator" xlink:label="us-gaap_DerivativeFairValueOfDerivativeNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeFairValueOfDerivativeNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Estimated fair value of derivative instruments from continuing operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeFairValueOfDerivativeNet" xlink:to="us-gaap_DerivativeFairValueOfDerivativeNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeFairValueOfDerivativeNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Fair Value Of Derivative Net</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities" xlink:type="locator" xlink:label="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit risk adjustment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities" xlink:to="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeCreditRiskValuationAdjustmentDerivativeLiabilities_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Credit Risk Valuation Adjustment Derivative Liabilities</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesEffectOfDerivativeInstrumentsOnOtherComprehensiveIncomeLossDetails" xlink:type="locator" xlink:label="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesEffectOfDerivativeInstrumentsOnOtherComprehensiveIncomeLossDetails" />
    <link:label xml:lang="en-US" xlink:label="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesEffectOfDerivativeInstrumentsOnOtherComprehensiveIncomeLossDetails_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Note 9 - Derivative Instruments and Hedging Strategies - Effect of Derivative Instruments on Other Comprehensive Income (Loss) (Details)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesEffectOfDerivativeInstrumentsOnOtherComprehensiveIncomeLossDetails" xlink:to="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesEffectOfDerivativeInstrumentsOnOtherComprehensiveIncomeLossDetails_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesEffectOfDerivativeInstrumentsOnOtherComprehensiveIncomeLossDetails_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Statement Note9 Derivative Instruments And Hedging Strategies Effect Of Derivative Instruments On Other Comprehensive Income Loss Details</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_JointVentureInterestRateSwapMember" xlink:type="locator" xlink:label="smhi_JointVentureInterestRateSwapMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_JointVentureInterestRateSwapMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information about joint venture interest rate swap.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_JointVentureInterestRateSwapMember" xlink:to="smhi_JointVentureInterestRateSwapMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_JointVentureInterestRateSwapMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Joint Venture Interest Rate Swap</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_JointVentureInterestRateSwapMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Joint Venture Interest Rate Swap [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesGainsLossesOnDerivativeInstrumentsDetails" xlink:type="locator" xlink:label="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesGainsLossesOnDerivativeInstrumentsDetails" />
    <link:label xml:lang="en-US" xlink:label="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesGainsLossesOnDerivativeInstrumentsDetails_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Note 9 - Derivative Instruments and Hedging Strategies - Gains (Losses) on Derivative Instruments (Details)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesGainsLossesOnDerivativeInstrumentsDetails" xlink:to="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesGainsLossesOnDerivativeInstrumentsDetails_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_StatementStatementNote9DerivativeInstrumentsAndHedgingStrategiesGainsLossesOnDerivativeInstrumentsDetails_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Statement Note9 Derivative Instruments And Hedging Strategies Gains Losses On Derivative Instruments Details</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_EmbeddedDerivativeFinancialInstrumentsMember" xlink:type="locator" xlink:label="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Embedded Derivative Financial Instruments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember" xlink:to="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_EmbeddedDerivativeFinancialInstrumentsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Embedded Derivative Financial Instruments [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ForeignExchangeOptionMember" xlink:type="locator" xlink:label="us-gaap_ForeignExchangeOptionMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignExchangeOptionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign Exchange Option</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ForeignExchangeOptionMember" xlink:to="us-gaap_ForeignExchangeOptionMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ForeignExchangeOptionMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Foreign Exchange Option [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gains (losses) on derivative instruments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet" xlink:to="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DerivativeInstrumentsNotDesignatedAsHedgingInstrumentsGainLossNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Derivative Instruments Not Designated As Hedging Instruments Gain Loss Net</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ProceedsToBeReceivedFromSaleOfBusiness" xlink:type="locator" xlink:label="smhi_ProceedsToBeReceivedFromSaleOfBusiness" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsToBeReceivedFromSaleOfBusiness_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Proceeds to be received from sale of business.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ProceedsToBeReceivedFromSaleOfBusiness" xlink:to="smhi_ProceedsToBeReceivedFromSaleOfBusiness_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsToBeReceivedFromSaleOfBusiness_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds to be received from sale of business</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ProceedsToBeReceivedFromSaleOfBusiness_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds To Be Received From Sale Of Business</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable" xlink:to="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fair Value Assets And Liabilities Measured On Recurring And Nonrecurring Basis [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueByFairValueHierarchyLevelAxis" xlink:type="locator" xlink:label="us-gaap_FairValueByFairValueHierarchyLevelAxis" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" xlink:type="locator" xlink:label="us-gaap_FairValueAssetsAndLiabilitiesMeasuredOnRecurringAndNonrecurringBasisLineItems" />
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DerivativeInstrumentsAndHedgesLiabilitiesNoncurrent" xlink:type="locator" xlink:label="us-gaap_DerivativeInstrumentsAndHedgesLiabilitiesNoncurrent" />
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    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfInvestmentsAtEquityInFiftyPercentOrLessOwnedCompaniesMarkedZeroDueToReturnOfFundsThatExceededTheCarryingValueInvestmentAndContinuedLosses" xlink:type="locator" xlink:label="smhi_NumberOfInvestmentsAtEquityInFiftyPercentOrLessOwnedCompaniesMarkedZeroDueToReturnOfFundsThatExceededTheCarryingValueInvestmentAndContinuedLosses" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfInvestmentsAtEquityInFiftyPercentOrLessOwnedCompaniesMarkedZeroDueToReturnOfFundsThatExceededTheCarryingValueInvestmentAndContinuedLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of investments, at equity, in 50% or less owned companies marked zero due to return of funds that exceeded the carrying value investment and continued losses.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfInvestmentsAtEquityInFiftyPercentOrLessOwnedCompaniesMarkedZeroDueToReturnOfFundsThatExceededTheCarryingValueInvestmentAndContinuedLosses" xlink:to="smhi_NumberOfInvestmentsAtEquityInFiftyPercentOrLessOwnedCompaniesMarkedZeroDueToReturnOfFundsThatExceededTheCarryingValueInvestmentAndContinuedLosses_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InvestmentOwnedExcessAmountFairValue" xlink:type="locator" xlink:label="smhi_InvestmentOwnedExcessAmountFairValue" />
    <link:label xml:lang="en-US" xlink:label="smhi_InvestmentOwnedExcessAmountFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Investment owned excess amount fair value.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InvestmentOwnedExcessAmountFairValue" xlink:to="smhi_InvestmentOwnedExcessAmountFairValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfInvestmentsAtEquityInFiftyPercentOrLessOwnedCompaniesMarkedZeroDueToReturnOfFundsThatExceededTheCarryingValueInvestmentAndContinuedLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of marked investments, at equity, in 50% or less owned companies</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfInvestmentsAtEquityInFiftyPercentOrLessOwnedCompaniesMarkedZeroDueToReturnOfFundsThatExceededTheCarryingValueInvestmentAndContinuedLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Investments At Equity In Fifty Percent Or Less Owned Companies Marked Zero Due To Return Of Funds That Exceeded The Carrying Value Investment And Continued Losses</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_EquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveTerseLabel">Investments, at equity, in 50% or less owned companies</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentOwnedAtFairValue" xlink:type="locator" xlink:label="us-gaap_InvestmentOwnedAtFairValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentOwnedAtFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment owned, at fair value, in 50% or less owned company</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentOwnedAtFairValue" xlink:to="us-gaap_InvestmentOwnedAtFairValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentOwnedAtFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment Owned At Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InvestmentOwnedExcessAmountFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment owned excess amount fair value, in 50% or less owned company</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InvestmentOwnedExcessAmountFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment Owned Excess Amount Fair Value</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InvestmentOwnedBalancePrincipalAmount" xlink:type="locator" xlink:label="us-gaap_InvestmentOwnedBalancePrincipalAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentOwnedBalancePrincipalAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investment owned, balance, in 50% or less owned company</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InvestmentOwnedBalancePrincipalAmount" xlink:to="us-gaap_InvestmentOwnedBalancePrincipalAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InvestmentOwnedBalancePrincipalAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investment Owned Balance Principal Amount</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ClassOfWarrantOrRightExercisedDuringPeriod" xlink:type="locator" xlink:label="smhi_ClassOfWarrantOrRightExercisedDuringPeriod" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClassOfWarrantOrRightExercisedDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The number of warrants or rights exercised during period.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ClassOfWarrantOrRightExercisedDuringPeriod" xlink:to="smhi_ClassOfWarrantOrRightExercisedDuringPeriod_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_StockIssuedDuringPeriodSharesWarrantsExercisedSharesWithHeldAsPaymentOfExercise" xlink:type="locator" xlink:label="smhi_StockIssuedDuringPeriodSharesWarrantsExercisedSharesWithHeldAsPaymentOfExercise" />
    <link:label xml:lang="en-US" xlink:label="smhi_StockIssuedDuringPeriodSharesWarrantsExercisedSharesWithHeldAsPaymentOfExercise_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Stock issued during period shares warrants exercised shares withheld as payment of exercise.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_StockIssuedDuringPeriodSharesWarrantsExercisedSharesWithHeldAsPaymentOfExercise" xlink:to="smhi_StockIssuedDuringPeriodSharesWarrantsExercisedSharesWithHeldAsPaymentOfExercise_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightTable" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class Of Warrant Or Right [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightTable" xlink:to="us-gaap_ClassOfWarrantOrRightTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrant Or Right [Table]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_WarrantsTransactionsMember" xlink:type="locator" xlink:label="smhi_WarrantsTransactionsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_WarrantsTransactionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Warrants transactions.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_WarrantsTransactionsMember" xlink:to="smhi_WarrantsTransactionsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_WarrantsTransactionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants Transactions</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_WarrantsTransactionsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Warrants Transactions [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightLineItems" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class Of Warrant Or Right [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightLineItems" xlink:to="us-gaap_ClassOfWarrantOrRightLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrant Or Right [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClassOfWarrantOrRightExercisedDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Class of warrant or right, exercised during period</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClassOfWarrantOrRightExercisedDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrant Or Right Exercised During Period</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightExercisePriceOfWarrantsOrRights1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Class of warrant or right, exercise price per share</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of warrant or right, number of securities called by warrants or rights</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights" xlink:to="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightNumberOfSecuritiesCalledByWarrantsOrRights_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrant Or Right Number Of Securities Called By Warrants Or Rights</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfWarrantOrRightOutstanding" xlink:type="locator" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of warrant or right, outstanding</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfWarrantOrRightOutstanding" xlink:to="us-gaap_ClassOfWarrantOrRightOutstanding_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfWarrantOrRightOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Warrant Or Right Outstanding</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_StockIssuedDuringPeriodSharesWarrantsExercisedSharesWithHeldAsPaymentOfExercise_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of shares withheld in an exercise to purchase warrants as payment for the exercise</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_StockIssuedDuringPeriodSharesWarrantsExercisedSharesWithHeldAsPaymentOfExercise_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stock Issued During Period Shares Warrants Exercised Shares With Held As Payment Of Exercise</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfStockByClassTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfStockByClassTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfStockByClassTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Stock By Class [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfStockByClassTable" xlink:to="us-gaap_ScheduleOfStockByClassTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfStockByClassTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Stock By Class [Table]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OSVPartnersOneMember" xlink:type="locator" xlink:label="smhi_OSVPartnersOneMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OSVPartnersOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">OSV Partners one.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OSVPartnersOneMember" xlink:to="smhi_OSVPartnersOneMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OSVPartnersOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">OSV Partners I</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OSVPartnersOneMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">O S V Partners One [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ExchangeWarrantsMember" xlink:type="locator" xlink:label="smhi_ExchangeWarrantsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExchangeWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents information about Exchange Warrants.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ExchangeWarrantsMember" xlink:to="smhi_ExchangeWarrantsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExchangeWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exchange Warrants</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ExchangeWarrantsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Exchange Warrants [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameAxis" xlink:type="locator" xlink:label="us-gaap_PlanNameAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameAxis" xlink:to="us-gaap_PlanNameAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PlanNameAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PlanNameDomain" xlink:type="locator" xlink:label="us-gaap_PlanNameDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PlanNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Plan Name</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PlanNameDomain" xlink:to="us-gaap_PlanNameDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PlanNameDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Plan Name [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TwoThousandSeventeenEquityIncentivePlanMember" xlink:type="locator" xlink:label="smhi_TwoThousandSeventeenEquityIncentivePlanMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenEquityIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Seventeen equity incentive plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TwoThousandSeventeenEquityIncentivePlanMember" xlink:to="smhi_TwoThousandSeventeenEquityIncentivePlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenEquityIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">2017 Equity Incentive Plan</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenEquityIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Seventeen Equity Incentive Plan [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TwoThousandTwentyEquityIncentivePlanMember" xlink:type="locator" xlink:label="smhi_TwoThousandTwentyEquityIncentivePlanMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandTwentyEquityIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two Thousand Twenty equity incentive plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TwoThousandTwentyEquityIncentivePlanMember" xlink:to="smhi_TwoThousandTwentyEquityIncentivePlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandTwentyEquityIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">2020 Equity Incentive Plan</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandTwentyEquityIncentivePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Twenty Equity Incentive Plan [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_FalconGlobalHoldingMember" xlink:type="locator" xlink:label="smhi_FalconGlobalHoldingMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalHoldingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Falcon global holding member.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_FalconGlobalHoldingMember" xlink:to="smhi_FalconGlobalHoldingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalHoldingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Falcon Global Holdings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FalconGlobalHoldingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Falcon Global Holding [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SeabulkOverseasMember" xlink:type="locator" xlink:label="smhi_SeabulkOverseasMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SeabulkOverseasMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents wholly owned subsidiary Seabulk Overseas.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SeabulkOverseasMember" xlink:to="smhi_SeabulkOverseasMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SeabulkOverseasMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Seabulk Overseas</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SeabulkOverseasMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Seabulk Overseas [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SubsidiarySaleOfStockAxis" xlink:type="locator" xlink:label="us-gaap_SubsidiarySaleOfStockAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SubsidiarySaleOfStockAxis" xlink:to="us-gaap_SubsidiarySaleOfStockAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SubsidiarySaleOfStockAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Subsidiary Sale Of Stock [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SaleOfStockNameOfTransactionDomain" xlink:type="locator" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sale of Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SaleOfStockNameOfTransactionDomain" xlink:to="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SaleOfStockNameOfTransactionDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sale Of Stock Name Of Transaction [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_PrivatePlacementMember" xlink:type="locator" xlink:label="us-gaap_PrivatePlacementMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PrivatePlacementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Private Placement</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_PrivatePlacementMember" xlink:to="us-gaap_PrivatePlacementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PrivatePlacementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Private Placement [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockLineItems" xlink:type="locator" xlink:label="us-gaap_ClassOfStockLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfStockLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class Of Stock [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfStockLineItems" xlink:to="us-gaap_ClassOfStockLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfStockLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Stock [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClassOfWarrantOrRightExercisedDuringPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of warrant or right, exercised during period</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:type="locator" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common shares registered for issuance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance" xlink:to="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockCapitalSharesReservedForFutureIssuance_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Common Stock Capital Shares Reserved For Future Issuance</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common shares authorized for issuance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Authorized</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Common shares remaining available for issuance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Number Of Shares Available For Grant</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Business acquisition, percentage of voting interests acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByParent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Ownership percentage by parent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_BusinessCombinationConsiderationTransferred1" xlink:type="locator" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Business combination, consideration transferred, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_BusinessCombinationConsiderationTransferred1" xlink:to="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Consideration Transferred1</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesNewIssues_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Stock Issued During Period, Shares, New Issues</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common stock value</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityIncludingPortionAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cumulative Effect of New Accounting Principle in Period of Adoption</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MinorityInterestTable" xlink:type="locator" xlink:label="us-gaap_MinorityInterestTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minority Interest [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestTable" xlink:to="us-gaap_MinorityInterestTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Minority Interest [Table]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_VEESEAHoldingsIncMember" xlink:type="locator" xlink:label="smhi_VEESEAHoldingsIncMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_VEESEAHoldingsIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">VEESEA Holdings Inc.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_VEESEAHoldingsIncMember" xlink:to="smhi_VEESEAHoldingsIncMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_VEESEAHoldingsIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">VEESEA Holdings Inc.</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_VEESEAHoldingsIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">V E E S E A Holdings Inc [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MinorityInterestLineItems" xlink:type="locator" xlink:label="us-gaap_MinorityInterestLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Minority Interest [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestLineItems" xlink:to="us-gaap_MinorityInterestLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Minority Interest [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_CommonStockMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Common Stock</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessAcquisitionPercentageOfVotingInterestsAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveLabel">Business acquisition, percentage of voting interests acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestOwnershipPercentageByNoncontrollingOwners_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Noncontrolling Interest, ownership percentage by parent</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProfitLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net income (loss), including portion attributable to noncontrolling interest, total</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_NetIncomeLossAttributableToNoncontrollingInterest_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net income (loss) attributable to noncontrolling interest, total</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PensionAndOtherPostretirementBenefitsDisclosureLineItems" xlink:type="locator" xlink:label="smhi_PensionAndOtherPostretirementBenefitsDisclosureLineItems" />
    <link:label xml:lang="en-US" xlink:label="smhi_PensionAndOtherPostretirementBenefitsDisclosureLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Pension and other postretirement benefits disclosure.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PensionAndOtherPostretirementBenefitsDisclosureLineItems" xlink:to="smhi_PensionAndOtherPostretirementBenefitsDisclosureLineItems_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PensionAndOtherPostretirementBenefitsDisclosureTable" xlink:type="locator" xlink:label="smhi_PensionAndOtherPostretirementBenefitsDisclosureTable" />
    <link:label xml:lang="en-US" xlink:label="smhi_PensionAndOtherPostretirementBenefitsDisclosureTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Pension and other postretirement benefits disclosure.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PensionAndOtherPostretirementBenefitsDisclosureTable" xlink:to="smhi_PensionAndOtherPostretirementBenefitsDisclosureTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PensionAndOtherPostretirementBenefitsDisclosureTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pension And Other Postretirement Benefits Disclosure [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PensionAndOtherPostretirementBenefitsDisclosureTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Pension And Other Postretirement Benefits Disclosure [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeAxis" xlink:type="locator" xlink:label="us-gaap_RetirementPlanTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetirementPlanTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retirement Plan Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanTypeAxis" xlink:to="us-gaap_RetirementPlanTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetirementPlanTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Retirement Plan Type [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RetirementPlanTypeDomain" xlink:type="locator" xlink:label="us-gaap_RetirementPlanTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetirementPlanTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Retirement Plan Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RetirementPlanTypeDomain" xlink:to="us-gaap_RetirementPlanTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RetirementPlanTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Retirement Plan Type [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OtherDefinedContributionPlanMember" xlink:type="locator" xlink:label="smhi_OtherDefinedContributionPlanMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDefinedContributionPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Related to other defined contribution plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OtherDefinedContributionPlanMember" xlink:to="smhi_OtherDefinedContributionPlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDefinedContributionPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Defined Contribution Plan</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDefinedContributionPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Defined Contribution Plan [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PensionAndOtherPostretirementBenefitsDisclosureLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Pension And Other Postretirement Benefits Disclosure [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PensionAndOtherPostretirementBenefitsDisclosureLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Pension And Other Postretirement Benefits Disclosure [Line Items]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:type="locator" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Defined contribution plan, employer matching contribution, percent of employees&apos; gross pay</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent" xlink:to="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanEmployerMatchingContributionPercent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Contribution Plan Employer Matching Contribution Percent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount" xlink:type="locator" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Defined Contribution Plan, Maximum Annual Contributions Per Employee, Amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount" xlink:to="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanMaximumAnnualContributionsPerEmployeeAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Contribution Plan Maximum Annual Contributions Per Employee Amount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DefinedContributionPlanCostRecognized" xlink:type="locator" xlink:label="us-gaap_DefinedContributionPlanCostRecognized" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanCostRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Defined contribution plan, cost</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DefinedContributionPlanCostRecognized" xlink:to="us-gaap_DefinedContributionPlanCostRecognized_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DefinedContributionPlanCostRecognized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Defined Contribution Plan Cost Recognized</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfNumberOfCommonStockSharesOutstanding" xlink:type="locator" xlink:label="smhi_PercentageOfNumberOfCommonStockSharesOutstanding" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfNumberOfCommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of number of common stock shares outstanding.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfNumberOfCommonStockSharesOutstanding" xlink:to="smhi_PercentageOfNumberOfCommonStockSharesOutstanding_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable" xlink:to="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfShareBasedCompensationArrangementsByShareBasedPaymentAwardTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Share Based Compensation Arrangements By Share Based Payment Award [Table]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityIncentivePlan2017Member" xlink:type="locator" xlink:label="smhi_EquityIncentivePlan2017Member" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityIncentivePlan2017Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity incentive plan 2017.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityIncentivePlan2017Member" xlink:to="smhi_EquityIncentivePlan2017Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityIncentivePlan2017Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2017 Equity Incentive Plan</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityIncentivePlan2017Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Incentive Plan2017 [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityIncentivePlan2017And2020Member" xlink:type="locator" xlink:label="smhi_EquityIncentivePlan2017And2020Member" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityIncentivePlan2017And2020Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity incentive plan 2017 and 2020.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityIncentivePlan2017And2020Member" xlink:to="smhi_EquityIncentivePlan2017And2020Member_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityIncentivePlan2017And2020Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2017 and 2020 Equity Incentive Plan</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityIncentivePlan2017And2020Member_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Incentive Plan2017 And2020 [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PerformanceRestrictedStockUnitsMember" xlink:type="locator" xlink:label="smhi_PerformanceRestrictedStockUnitsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PerformanceRestrictedStockUnitsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Performance restricted stock units.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PerformanceRestrictedStockUnitsMember" xlink:to="smhi_PerformanceRestrictedStockUnitsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PerformanceRestrictedStockUnitsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Performance Restricted Stock Units</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PerformanceRestrictedStockUnitsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Performance Restricted Stock Units [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EmployeeStockPurchasePlanMember" xlink:type="locator" xlink:label="smhi_EmployeeStockPurchasePlanMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_EmployeeStockPurchasePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Employee stock purchase plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EmployeeStockPurchasePlanMember" xlink:to="smhi_EmployeeStockPurchasePlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EmployeeStockPurchasePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Employee Stock Purchase Plan</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EmployeeStockPurchasePlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Employee Stock Purchase Plan [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TwoThousandSeventeenAndTwoThousandTwentyPlanMember" xlink:type="locator" xlink:label="smhi_TwoThousandSeventeenAndTwoThousandTwentyPlanMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenAndTwoThousandTwentyPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand seventeen and two thousand twenty plan.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TwoThousandSeventeenAndTwoThousandTwentyPlanMember" xlink:to="smhi_TwoThousandSeventeenAndTwoThousandTwentyPlanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenAndTwoThousandTwentyPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">2017 Plan and 2020 Plan</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenAndTwoThousandTwentyPlanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Seventeen And Two Thousand Twenty Plan [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share Based Compensation Arrangement By Share Based Payment Award [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAuthorized_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Share-based compensation arrangement by share-based payment award, number of shares authorized</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardNumberOfSharesAvailableForGrant_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Share-based compensation arrangement by share-based payment award, number of shares available for grant</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfNumberOfCommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of number of common stock shares outstanding</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfNumberOfCommonStockSharesOutstanding_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Number Of Common Stock Shares Outstanding</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based compensation arrangement by share-based payment award, award vesting period</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingPeriod1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Award Vesting Period1</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PaymentsForDistributionOfRestrictedStockSpinOff" xlink:type="locator" xlink:label="smhi_PaymentsForDistributionOfRestrictedStockSpinOff" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForDistributionOfRestrictedStockSpinOff_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The amount of payments for the distribution of restricted stock in connection with a spin-off.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PaymentsForDistributionOfRestrictedStockSpinOff" xlink:to="smhi_PaymentsForDistributionOfRestrictedStockSpinOff_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DistributionOfRestrictedStockInConnectionWithSpinoff" xlink:type="locator" xlink:label="smhi_DistributionOfRestrictedStockInConnectionWithSpinoff" />
    <link:label xml:lang="en-US" xlink:label="smhi_DistributionOfRestrictedStockInConnectionWithSpinoff_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The number of restricted stock distributed to the company in connection with a spin-off.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DistributionOfRestrictedStockInConnectionWithSpinoff" xlink:to="smhi_DistributionOfRestrictedStockInConnectionWithSpinoff_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForDistributionOfRestrictedStockSpinOff_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Payments for distribution of restricted stock, spin-off</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PaymentsForDistributionOfRestrictedStockSpinOff_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Payments For Distribution Of Restricted Stock Spin Off</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DistributionOfRestrictedStockInConnectionWithSpinoff_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Distribution of restricted stock in connection with spin-off</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DistributionOfRestrictedStockInConnectionWithSpinoff_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Distribution Of Restricted Stock In Connection With Spinoff</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based compensation arrangement by share-based payment award, discount from market price, purchase date</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardDiscountFromMarketPricePurchaseDate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Discount From Market Price Purchase Date</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Period of common stock reserved for issuance</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardExpirationPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sharebased Compensation Arrangement By Sharebased Payment Award Expiration Period</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DirectorStockAwardsMember" xlink:type="locator" xlink:label="smhi_DirectorStockAwardsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_DirectorStockAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Director stock awards.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DirectorStockAwardsMember" xlink:to="smhi_DirectorStockAwardsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_DirectorStockAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Director Stock Awards</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DirectorStockAwardsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Director Stock Awards [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Outstanding as of the beginning of year (in shares)</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsGrantsInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Granted (in shares)</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vested (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsVestedInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Vested In Period</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Forfeited (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsForfeitedInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Equity Instruments Other Than Options Forfeited In Period</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardEquityInstrumentsOtherThanOptionsNonvestedNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Outstanding as of the end of year (in shares)</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodStartLabel">Outstanding as of the beginning of year (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Number</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Granted (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPeriodGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Grants In Period Gross</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockIssuedDuringPeriodSharesStockOptionsExercised_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveLabel">Exercised (in shares)</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Forfeited (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriod_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Forfeitures In Period</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Outstanding as of the end of year (in shares)</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriodBeforeAdjustment" xlink:type="locator" xlink:label="smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriodBeforeAdjustment" />
    <link:label xml:lang="en-US" xlink:label="smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriodBeforeAdjustment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award options forfeitures in period before adjustment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriodBeforeAdjustment" xlink:to="smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsForfeituresInPeriodBeforeAdjustment_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPreviousPeriodGross" xlink:type="locator" xlink:label="smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPreviousPeriodGross" />
    <link:label xml:lang="en-US" xlink:label="smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPreviousPeriodGross_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Share based compensation arrangement by share based payment award options grants in previous period gross.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPreviousPeriodGross" xlink:to="smhi_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsGrantsInPreviousPeriodGross_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_PerformanceSharesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Performance Stock</link:label>
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    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingWeightedAverageExercisePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Weighted Average Exercise Price</link:label>
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    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Exercised (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementsByShareBasedPaymentAwardOptionsExercisesInPeriodWeightedAverageExercisePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangements By Share Based Payment Award Options Exercises In Period Weighted Average Exercise Price</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Forfeited, shares (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedNumberOfShares_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Options Forfeited Number Of Shares</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Forfeited, weight average grant price (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedOptionsForfeitedWeightedAverageGrantDateFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sharebased Compensation Arrangement By Sharebased Payment Award Options Nonvested Options Forfeited Weighted Average Grant Date Fair Value</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedNumberOfShares_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Non-Vested, shares (in shares)</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsNonvestedWeightedAverageGrantDateFairValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/periodEndLabel">Non-Vested, weight average grant price (in dollars per share)</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercisable, shares (in shares)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableNumber_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Number</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exercisable, weight average grant price (in dollars per share)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsExercisableWeightedAverageExercisePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Exercisable Weighted Average Exercise Price</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:type="locator" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based compensation arrangement by share-based payment award, options, exercisable, weighted average remaining contractual term</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1" xlink:to="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsExercisableWeightedAverageRemainingContractualTerm1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sharebased Compensation Arrangement By Sharebased Payment Award Options Exercisable Weighted Average Remaining Contractual Term1</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:type="locator" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Share-based compensation arrangement by share-based payment award, options, outstanding, intrinsic value</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue" xlink:to="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ShareBasedCompensationArrangementByShareBasedPaymentAwardOptionsOutstandingIntrinsicValue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Share Based Compensation Arrangement By Share Based Payment Award Options Outstanding Intrinsic Value</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_RelatedPartyTransactionsMinimumAmountOfTransactionsForReviewAndApproval" xlink:type="locator" xlink:label="smhi_RelatedPartyTransactionsMinimumAmountOfTransactionsForReviewAndApproval" />
    <link:label xml:lang="en-US" xlink:label="smhi_RelatedPartyTransactionsMinimumAmountOfTransactionsForReviewAndApproval_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Related party transactions minimum amount of transactions for review and approval.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_RelatedPartyTransactionsMinimumAmountOfTransactionsForReviewAndApproval" xlink:to="smhi_RelatedPartyTransactionsMinimumAmountOfTransactionsForReviewAndApproval_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Related Party Transactions By Related Party [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable" xlink:to="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfRelatedPartyTransactionsByRelatedPartyTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Related Party Transactions By Related Party [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis" xlink:to="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionsByRelatedPartyAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transactions By Related Party [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyDomain" xlink:type="locator" xlink:label="us-gaap_RelatedPartyDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyDomain" xlink:to="us-gaap_RelatedPartyDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Related Party [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SEACORHoldingsMember" xlink:type="locator" xlink:label="smhi_SEACORHoldingsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to SEACOR Holdings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SEACORHoldingsMember" xlink:to="smhi_SEACORHoldingsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">SEACOR Holdings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SEACORHoldingsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">S E A C O R Holdings [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionAxis" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party Transaction</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionAxis" xlink:to="us-gaap_RelatedPartyTransactionAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transaction [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionDomain" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party Transaction</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionDomain" xlink:to="us-gaap_RelatedPartyTransactionDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transaction [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TransitionServicesAgreementMember" xlink:type="locator" xlink:label="smhi_TransitionServicesAgreementMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TransitionServicesAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Transition services agreement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TransitionServicesAgreementMember" xlink:to="smhi_TransitionServicesAgreementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TransitionServicesAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Transition Services Agreement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TransitionServicesAgreementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Transition Services Agreement [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualAxis" xlink:type="locator" xlink:label="srt_TitleOfIndividualAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_TitleOfIndividualAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Title of Individual</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_TitleOfIndividualAxis" xlink:to="srt_TitleOfIndividualAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_TitleOfIndividualAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Title Of Individual [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:type="locator" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Title of Individual</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_TitleOfIndividualWithRelationshipToEntityDomain" xlink:to="srt_TitleOfIndividualWithRelationshipToEntityDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_TitleOfIndividualWithRelationshipToEntityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Title Of Individual With Relationship To Entity [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NonExecutiveChairmanMember" xlink:type="locator" xlink:label="smhi_NonExecutiveChairmanMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_NonExecutiveChairmanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Non-executive chairman.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NonExecutiveChairmanMember" xlink:to="smhi_NonExecutiveChairmanMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_NonExecutiveChairmanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Mr. Fabrikant</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NonExecutiveChairmanMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Non Executive Chairman [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PresidentChiefExecutiveOfficerAndDirectorMember" xlink:type="locator" xlink:label="smhi_PresidentChiefExecutiveOfficerAndDirectorMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PresidentChiefExecutiveOfficerAndDirectorMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">President, Chief Executive Officer and Director.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PresidentChiefExecutiveOfficerAndDirectorMember" xlink:to="smhi_PresidentChiefExecutiveOfficerAndDirectorMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PresidentChiefExecutiveOfficerAndDirectorMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gellert</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PresidentChiefExecutiveOfficerAndDirectorMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">President Chief Executive Officer And Director [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ExecutiveVicePresidentAndChiefFinancialOfficerMember" xlink:type="locator" xlink:label="smhi_ExecutiveVicePresidentAndChiefFinancialOfficerMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExecutiveVicePresidentAndChiefFinancialOfficerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Executive vice president and chief financial officer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ExecutiveVicePresidentAndChiefFinancialOfficerMember" xlink:to="smhi_ExecutiveVicePresidentAndChiefFinancialOfficerMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExecutiveVicePresidentAndChiefFinancialOfficerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Llorca</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ExecutiveVicePresidentAndChiefFinancialOfficerMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Executive Vice President And Chief Financial Officer [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CarolineMember" xlink:type="locator" xlink:label="smhi_CarolineMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarolineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Caroline.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CarolineMember" xlink:to="smhi_CarolineMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarolineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Caroline</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CarolineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Caroline [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CarolineIIMember" xlink:type="locator" xlink:label="smhi_CarolineIIMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarolineIIMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Caroline II.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CarolineIIMember" xlink:to="smhi_CarolineIIMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CarolineIIMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Caroline I I</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CarolineIIMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Caroline I I [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TwoThousandSeventeenPreferredInterestsMember" xlink:type="locator" xlink:label="smhi_TwoThousandSeventeenPreferredInterestsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Two thousand seventeen preferred interests.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TwoThousandSeventeenPreferredInterestsMember" xlink:to="smhi_TwoThousandSeventeenPreferredInterestsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Two Thousand Seventeen Preferred Interests</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TwoThousandSeventeenPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Two Thousand Seventeen Preferred Interests [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ClassAPreferredInterestsMember" xlink:type="locator" xlink:label="smhi_ClassAPreferredInterestsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Class A Preferred Interests.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ClassAPreferredInterestsMember" xlink:to="smhi_ClassAPreferredInterestsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class A Preferred Interests</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class A Preferred Interests [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SecondLienDebtMember" xlink:type="locator" xlink:label="smhi_SecondLienDebtMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SecondLienDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Second Lien Debt.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SecondLienDebtMember" xlink:to="smhi_SecondLienDebtMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SecondLienDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Second Lien Debt</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SecondLienDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Second Lien Debt [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ClassAPreferredInterestsCarolineMember" xlink:type="locator" xlink:label="smhi_ClassAPreferredInterestsCarolineMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsCarolineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Class A preferred interests caroline.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ClassAPreferredInterestsCarolineMember" xlink:to="smhi_ClassAPreferredInterestsCarolineMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsCarolineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class A Preferred Interests Caroline</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsCarolineMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class A Preferred Interests Caroline [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PIKLoanDebtAndCarolineTwoMember" xlink:type="locator" xlink:label="smhi_PIKLoanDebtAndCarolineTwoMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PIKLoanDebtAndCarolineTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">PIK Loan Debt, and Caroline II.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PIKLoanDebtAndCarolineTwoMember" xlink:to="smhi_PIKLoanDebtAndCarolineTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PIKLoanDebtAndCarolineTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">P I K Loan Debt And Caroline</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PIKLoanDebtAndCarolineTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">P I K Loan Debt And Caroline Two [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ClassAPreferredInterestsCarolineTwoMember" xlink:type="locator" xlink:label="smhi_ClassAPreferredInterestsCarolineTwoMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsCarolineTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Class A preferred interests caroline two.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ClassAPreferredInterestsCarolineTwoMember" xlink:to="smhi_ClassAPreferredInterestsCarolineTwoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsCarolineTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class A Preferred Interests Caroline II</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ClassAPreferredInterestsCarolineTwoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class A Preferred Interests Caroline Two [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PIKLoanDebtMember" xlink:type="locator" xlink:label="smhi_PIKLoanDebtMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PIKLoanDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">PIK loan debt.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PIKLoanDebtMember" xlink:to="smhi_PIKLoanDebtMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PIKLoanDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">P I K Loan Debt And Caroline II</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PIKLoanDebtMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">P I K Loan Debt [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ExchangeMember" xlink:type="locator" xlink:label="smhi_ExchangeMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExchangeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Exchange.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ExchangeMember" xlink:to="smhi_ExchangeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExchangeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exchange</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ExchangeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Exchange [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ThirdPartyLenderMember" xlink:type="locator" xlink:label="smhi_ThirdPartyLenderMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ThirdPartyLenderMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Third-party lender.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ThirdPartyLenderMember" xlink:to="smhi_ThirdPartyLenderMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ThirdPartyLenderMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Third Party Lender</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ThirdPartyLenderMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Third Party Lender [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PrincipalMember" xlink:type="locator" xlink:label="smhi_PrincipalMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PrincipalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Principal.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PrincipalMember" xlink:to="smhi_PrincipalMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PrincipalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Principal</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PrincipalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Principal [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityAxis" xlink:type="locator" xlink:label="us-gaap_CreditFacilityAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CreditFacilityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityAxis" xlink:to="us-gaap_CreditFacilityAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CreditFacilityAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CreditFacilityDomain" xlink:type="locator" xlink:label="us-gaap_CreditFacilityDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CreditFacilityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Credit Facility</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CreditFacilityDomain" xlink:to="us-gaap_CreditFacilityDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CreditFacilityDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Credit Facility [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OSVCreditFacilityMember" xlink:type="locator" xlink:label="smhi_OSVCreditFacilityMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OSVCreditFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">OSV credit facility.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OSVCreditFacilityMember" xlink:to="smhi_OSVCreditFacilityMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OSVCreditFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">O S V Credit Facility</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OSVCreditFacilityMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">O S V Credit Facility [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StatementClassOfStockAxis" xlink:type="locator" xlink:label="us-gaap_StatementClassOfStockAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StatementClassOfStockAxis" xlink:to="us-gaap_StatementClassOfStockAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StatementClassOfStockAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Statement Class Of Stock [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ClassOfStockDomain" xlink:type="locator" xlink:label="us-gaap_ClassOfStockDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfStockDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Class of Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ClassOfStockDomain" xlink:to="us-gaap_ClassOfStockDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ClassOfStockDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Class Of Stock [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PreferredInterestsAndClassAPreferredInterestsMember" xlink:type="locator" xlink:label="smhi_PreferredInterestsAndClassAPreferredInterestsMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PreferredInterestsAndClassAPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Preferred interests and Class A preferred interests.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PreferredInterestsAndClassAPreferredInterestsMember" xlink:to="smhi_PreferredInterestsAndClassAPreferredInterestsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PreferredInterestsAndClassAPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred Interests and Class A Preferred Interests</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PreferredInterestsAndClassAPreferredInterestsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Preferred Interests And Class A Preferred Interests [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_MergerConsiderationAndPaymentInKindLoanConsiderationMember" xlink:type="locator" xlink:label="smhi_MergerConsiderationAndPaymentInKindLoanConsiderationMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_MergerConsiderationAndPaymentInKindLoanConsiderationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Merger consideration and payment in kind loan consideration.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_MergerConsiderationAndPaymentInKindLoanConsiderationMember" xlink:to="smhi_MergerConsiderationAndPaymentInKindLoanConsiderationMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_MergerConsiderationAndPaymentInKindLoanConsiderationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Merger Consideration And Payment In Kind Loan Consideration</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_MergerConsiderationAndPaymentInKindLoanConsiderationMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Merger Consideration And Payment In Kind Loan Consideration [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CMBNVMember" xlink:type="locator" xlink:label="smhi_CMBNVMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_CMBNVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">CMB N.V.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CMBNVMember" xlink:to="smhi_CMBNVMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CMBNVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">CMB N.V.</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CMBNVMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">C M B N V [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_WarrantsIssuedInPrivatePlacementMember" xlink:type="locator" xlink:label="smhi_WarrantsIssuedInPrivatePlacementMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_WarrantsIssuedInPrivatePlacementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Represents the warrants issued in a private placement.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_WarrantsIssuedInPrivatePlacementMember" xlink:to="smhi_WarrantsIssuedInPrivatePlacementMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_WarrantsIssuedInPrivatePlacementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Warrants Issued In Private Placement</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_WarrantsIssuedInPrivatePlacementMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Warrants Issued In Private Placement [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LenderNonRecourseMember" xlink:type="locator" xlink:label="smhi_LenderNonRecourseMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_LenderNonRecourseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Lender non recourse.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LenderNonRecourseMember" xlink:to="smhi_LenderNonRecourseMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_LenderNonRecourseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lender Non Recourse</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LenderNonRecourseMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Lender Non Recourse [Member]</link:label>
    <link:loc xlink:href="https://xbrl.sec.gov/country/2021/country-2021.xsd#country_BR" xlink:type="locator" xlink:label="country_BR" />
    <link:label xml:lang="en-US" xlink:label="country_BR_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">BRAZIL</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="country_BR" xlink:to="country_BR_lbl" />
    <link:label xml:lang="en-US" xlink:label="country_BR_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">BRAZIL</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OPEMMember" xlink:type="locator" xlink:label="smhi_OPEMMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OPEMMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">OPEM.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OPEMMember" xlink:to="smhi_OPEMMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OPEMMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">O P E M</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OPEMMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">O P E M [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SubsidiaryOfMexMarMember" xlink:type="locator" xlink:label="smhi_SubsidiaryOfMexMarMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SubsidiaryOfMexMarMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Subsidiary of MexMar.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SubsidiaryOfMexMarMember" xlink:to="smhi_SubsidiaryOfMexMarMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SubsidiaryOfMexMarMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Subsidiary of MexMar</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SubsidiaryOfMexMarMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Subsidiary Of Mex Mar [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TalosEnergyIncMember" xlink:type="locator" xlink:label="smhi_TalosEnergyIncMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TalosEnergyIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Talos energy, Inc.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TalosEnergyIncMember" xlink:to="smhi_TalosEnergyIncMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TalosEnergyIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Talos Energy, Inc</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TalosEnergyIncMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Talos Energy Inc [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionLineItems" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party Transaction [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionLineItems" xlink:to="us-gaap_RelatedPartyTransactionLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transaction [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_RelatedPartyTransactionsMinimumAmountOfTransactionsForReviewAndApproval_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related party transactions,minimum amount of transaction for review and approval</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_RelatedPartyTransactionsMinimumAmountOfTransactionsForReviewAndApproval_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transactions Minimum Amount Of Transactions For Review And Approval</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GuaranteeObligationsMaximumExposure" xlink:type="locator" xlink:label="us-gaap_GuaranteeObligationsMaximumExposure" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsMaximumExposure_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Guarantor obligations, maximum exposure</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GuaranteeObligationsMaximumExposure" xlink:to="us-gaap_GuaranteeObligationsMaximumExposure_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GuaranteeObligationsMaximumExposure_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Guarantee Obligations Maximum Exposure</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionRate" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionRate" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related party transaction, rate</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionRate" xlink:to="us-gaap_RelatedPartyTransactionRate_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionRate_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transaction Rate</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_InterestExpenseRelatedParty" xlink:type="locator" xlink:label="us-gaap_InterestExpenseRelatedParty" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestExpenseRelatedParty_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest expense, related party</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_InterestExpenseRelatedParty" xlink:to="us-gaap_InterestExpenseRelatedParty_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_InterestExpenseRelatedParty_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Expense Related Party</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InterestReceived" xlink:type="locator" xlink:label="smhi_InterestReceived" />
    <link:label xml:lang="en-US" xlink:label="smhi_InterestReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Interest received.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InterestReceived" xlink:to="smhi_InterestReceived_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TaxRefundsRestrictedCash" xlink:type="locator" xlink:label="smhi_TaxRefundsRestrictedCash" />
    <link:label xml:lang="en-US" xlink:label="smhi_TaxRefundsRestrictedCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Tax refunds restricted cash.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TaxRefundsRestrictedCash" xlink:to="smhi_TaxRefundsRestrictedCash_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIncomeTaxRefunds_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Proceeds from cash tax refunds</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest received on cash refunds</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InterestReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Interest Received</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TaxRefundsRestrictedCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Tax refunds restricted cash</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TaxRefundsRestrictedCash_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Tax Refunds Restricted Cash</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_RelatedPartyTransactionAmountsOfTransaction" xlink:type="locator" xlink:label="us-gaap_RelatedPartyTransactionAmountsOfTransaction" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionAmountsOfTransaction_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Related Party Transaction, Amounts of Transaction</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_RelatedPartyTransactionAmountsOfTransaction" xlink:to="us-gaap_RelatedPartyTransactionAmountsOfTransaction_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_RelatedPartyTransactionAmountsOfTransaction_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Related Party Transaction Amounts Of Transaction</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfInitialLimitedPartnerInterestsAndGeneralPartnerInterestsAndInitialLpInterestsHeldByUnrelatedThirdParties" xlink:type="locator" xlink:label="smhi_PercentageOfInitialLimitedPartnerInterestsAndGeneralPartnerInterestsAndInitialLpInterestsHeldByUnrelatedThirdParties" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfInitialLimitedPartnerInterestsAndGeneralPartnerInterestsAndInitialLpInterestsHeldByUnrelatedThirdParties_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of initial limited partner interests and general partner interests and initial lp interests held by unrelated third parties.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfInitialLimitedPartnerInterestsAndGeneralPartnerInterestsAndInitialLpInterestsHeldByUnrelatedThirdParties" xlink:to="smhi_PercentageOfInitialLimitedPartnerInterestsAndGeneralPartnerInterestsAndInitialLpInterestsHeldByUnrelatedThirdParties_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfInitialLimitedPartnerInterestsAndGeneralPartnerInterestsAndInitialLpInterestsHeldByUnrelatedThirdParties_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of initial limited partner interests and general partner interests and initial lp interests held by unrelated third parties</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfInitialLimitedPartnerInterestsAndGeneralPartnerInterestsAndInitialLpInterestsHeldByUnrelatedThirdParties_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Initial Limited Partner Interests And General Partner Interests And Initial Lp Interests Held By Unrelated Third Parties</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_Investments" xlink:type="locator" xlink:label="us-gaap_Investments" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Investments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Investments</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_Investments" xlink:to="us-gaap_Investments_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_Investments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Investments</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_EquityMethodInvestmentOwnershipAmount" xlink:type="locator" xlink:label="smhi_EquityMethodInvestmentOwnershipAmount" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Equity method investment, ownership amount.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_EquityMethodInvestmentOwnershipAmount" xlink:to="smhi_EquityMethodInvestmentOwnershipAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Equity Method Investment, Ownership Amount</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_EquityMethodInvestmentOwnershipAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Equity Method Investment Ownership Amount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_MinorityInterestInPreferredUnitHolders" xlink:type="locator" xlink:label="us-gaap_MinorityInterestInPreferredUnitHolders" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestInPreferredUnitHolders_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Preferred limited partnership interests</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_MinorityInterestInPreferredUnitHolders" xlink:to="us-gaap_MinorityInterestInPreferredUnitHolders_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_MinorityInterestInPreferredUnitHolders_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Minority Interest In Preferred Unit Holders</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromSaleOfInterestInPartnershipUnit" xlink:type="locator" xlink:label="us-gaap_ProceedsFromSaleOfInterestInPartnershipUnit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromSaleOfInterestInPartnershipUnit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from Sale of Interest in Partnership Unit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromSaleOfInterestInPartnershipUnit" xlink:to="us-gaap_ProceedsFromSaleOfInterestInPartnershipUnit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromSaleOfInterestInPartnershipUnit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Sale Of Interest In Partnership Unit</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ProceedsFromIssuanceOfRedeemablePreferredStock" xlink:type="locator" xlink:label="us-gaap_ProceedsFromIssuanceOfRedeemablePreferredStock" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIssuanceOfRedeemablePreferredStock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Proceeds from Issuance of Redeemable Preferred Stock</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ProceedsFromIssuanceOfRedeemablePreferredStock" xlink:to="us-gaap_ProceedsFromIssuanceOfRedeemablePreferredStock_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ProceedsFromIssuanceOfRedeemablePreferredStock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Proceeds From Issuance Of Redeemable Preferred Stock</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LimitedPartnersCapitalAccount" xlink:type="locator" xlink:label="us-gaap_LimitedPartnersCapitalAccount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LimitedPartnersCapitalAccount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Limited Partners&apos; Capital Account</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LimitedPartnersCapitalAccount" xlink:to="us-gaap_LimitedPartnersCapitalAccount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LimitedPartnersCapitalAccount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Limited Partners Capital Account</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_VesselManagementFees" xlink:type="locator" xlink:label="smhi_VesselManagementFees" />
    <link:label xml:lang="en-US" xlink:label="smhi_VesselManagementFees_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Vessel management fees.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_VesselManagementFees" xlink:to="smhi_VesselManagementFees_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_VesselManagementFees_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Vessel management fees</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_VesselManagementFees_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Vessel Management Fees</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LoanAcquired" xlink:type="locator" xlink:label="smhi_LoanAcquired" />
    <link:label xml:lang="en-US" xlink:label="smhi_LoanAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Loan acquired.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LoanAcquired" xlink:to="smhi_LoanAcquired_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_LoanAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loan acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LoanAcquired_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Loan Acquired</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OwnershipPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Ownership Percentage</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_BusinessCombinationConsiderationTransferred1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Business combination, consideration transferred, total</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageSaleOfEquity" xlink:type="locator" xlink:label="smhi_PercentageSaleOfEquity" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageSaleOfEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage sale of equity.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageSaleOfEquity" xlink:to="smhi_PercentageSaleOfEquity_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageSaleOfEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage sale of equity</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageSaleOfEquity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Sale Of Equity</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentInterestRateTerms" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentInterestRateTerms" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentInterestRateTerms_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest rate term</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentInterestRateTerms" xlink:to="us-gaap_DebtInstrumentInterestRateTerms_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentInterestRateTerms_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Interest Rate Terms</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PercentageOfConvertibleNotesConvertedIntoCommonStock" xlink:type="locator" xlink:label="smhi_PercentageOfConvertibleNotesConvertedIntoCommonStock" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfConvertibleNotesConvertedIntoCommonStock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Percentage of convertible notes converted into common stock.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PercentageOfConvertibleNotesConvertedIntoCommonStock" xlink:to="smhi_PercentageOfConvertibleNotesConvertedIntoCommonStock_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfConvertibleNotesConvertedIntoCommonStock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage of convertible notes converted into common stock</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PercentageOfConvertibleNotesConvertedIntoCommonStock_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Percentage Of Convertible Notes Converted Into Common Stock</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature" xlink:type="locator" xlink:label="us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Debt instrument, convertible, terms of conversion feature</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature" xlink:to="us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DebtInstrumentConvertibleTermsOfConversionFeature_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Instrument Convertible Terms Of Conversion Feature</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DebtIndebtedness" xlink:type="locator" xlink:label="smhi_DebtIndebtedness" />
    <link:label xml:lang="en-US" xlink:label="smhi_DebtIndebtedness_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Debt indebtedness.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DebtIndebtedness" xlink:to="smhi_DebtIndebtedness_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_DebtIndebtedness_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Indebtedness</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DebtIndebtedness_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Debt Indebtedness</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LongTermPurchaseCommitmentAmount" xlink:type="locator" xlink:label="us-gaap_LongTermPurchaseCommitmentAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermPurchaseCommitmentAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitment to fund purchase</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LongTermPurchaseCommitmentAmount" xlink:to="us-gaap_LongTermPurchaseCommitmentAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LongTermPurchaseCommitmentAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Long Term Purchase Commitment Amount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent" xlink:type="locator" xlink:label="us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loaned commitment amount</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent" xlink:to="us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NotesPayableRelatedPartiesCurrentAndNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Notes Payable Related Parties Current And Noncurrent</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TotalPurchasePrice" xlink:type="locator" xlink:label="smhi_TotalPurchasePrice" />
    <link:label xml:lang="en-US" xlink:label="smhi_TotalPurchasePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Total purchase price.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TotalPurchasePrice" xlink:to="smhi_TotalPurchasePrice_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_GainLossOnEquityEarnings" xlink:type="locator" xlink:label="smhi_GainLossOnEquityEarnings" />
    <link:label xml:lang="en-US" xlink:label="smhi_GainLossOnEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Gain (loss) on equity earnings.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_GainLossOnEquityEarnings" xlink:to="smhi_GainLossOnEquityEarnings_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DistributionReceived" xlink:type="locator" xlink:label="smhi_DistributionReceived" />
    <link:label xml:lang="en-US" xlink:label="smhi_DistributionReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Distribution received.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DistributionReceived" xlink:to="smhi_DistributionReceived_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ExcessOfDistributionReceived" xlink:type="locator" xlink:label="smhi_ExcessOfDistributionReceived" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExcessOfDistributionReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Excess of distribution received.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ExcessOfDistributionReceived" xlink:to="smhi_ExcessOfDistributionReceived_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TotalPurchasePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total purchase price</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TotalPurchasePrice_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Total Purchase Price</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_GainLossOnEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain (loss) on equity earnings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_GainLossOnEquityEarnings_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Gain Loss On Equity Earnings</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DistributionReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Distribution Received</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DistributionReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Distribution Received</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ExcessOfDistributionReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Excess of distribution received</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ExcessOfDistributionReceived_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Excess Of Distribution Received</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_BusinessCombinationConsiderationTransferredPercentage" xlink:type="locator" xlink:label="smhi_BusinessCombinationConsiderationTransferredPercentage" />
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationConsiderationTransferredPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Business combination, consideration transferred percentage.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_BusinessCombinationConsiderationTransferredPercentage" xlink:to="smhi_BusinessCombinationConsiderationTransferredPercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationConsiderationTransferredPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Percentage transferred</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BusinessCombinationConsiderationTransferredPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Business Combination Consideration Transferred Percentage</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LoanInExchange" xlink:type="locator" xlink:label="smhi_LoanInExchange" />
    <link:label xml:lang="en-US" xlink:label="smhi_LoanInExchange_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Loan in exchange.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LoanInExchange" xlink:to="smhi_LoanInExchange_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_LoanEarlyRepayment" xlink:type="locator" xlink:label="smhi_LoanEarlyRepayment" />
    <link:label xml:lang="en-US" xlink:label="smhi_LoanEarlyRepayment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Loan early repayment.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_LoanEarlyRepayment" xlink:to="smhi_LoanEarlyRepayment_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_LoanInExchange_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loan in exchange</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LoanInExchange_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Loan In Exchange</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LoanEarlyRepayment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Loan early repayment</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_LoanEarlyRepayment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Loan Early Repayment</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/positiveTerseLabel">Revenues</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CommitmentsAndContingenciesLineItems" xlink:type="locator" xlink:label="smhi_CommitmentsAndContingenciesLineItems" />
    <link:label xml:lang="en-US" xlink:label="smhi_CommitmentsAndContingenciesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Commitments and contingencies.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CommitmentsAndContingenciesLineItems" xlink:to="smhi_CommitmentsAndContingenciesLineItems_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CommitmentsAndContingenciesTable" xlink:type="locator" xlink:label="smhi_CommitmentsAndContingenciesTable" />
    <link:label xml:lang="en-US" xlink:label="smhi_CommitmentsAndContingenciesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Commitments and contingencies.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CommitmentsAndContingenciesTable" xlink:to="smhi_CommitmentsAndContingenciesTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CommitmentsAndContingenciesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments And Contingencies [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CommitmentsAndContingenciesTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Commitments And Contingencies [Table]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FSVOffshoreSupportVesselsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">FSV Offshore Support Vessels</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LitigationCaseAxis" xlink:type="locator" xlink:label="srt_LitigationCaseAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_LitigationCaseAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Litigation Case</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_LitigationCaseAxis" xlink:to="srt_LitigationCaseAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_LitigationCaseAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Litigation Case [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_LitigationCaseTypeDomain" xlink:type="locator" xlink:label="srt_LitigationCaseTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_LitigationCaseTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Litigation Case</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_LitigationCaseTypeDomain" xlink:to="srt_LitigationCaseTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_LitigationCaseTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Litigation Case Type [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DeficiencyNoticeMember" xlink:type="locator" xlink:label="smhi_DeficiencyNoticeMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_DeficiencyNoticeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Deficiency notice.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DeficiencyNoticeMember" xlink:to="smhi_DeficiencyNoticeMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_DeficiencyNoticeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Deficiency Notice</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DeficiencyNoticeMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Deficiency Notice [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CommitmentsAndContingenciesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Commitments And Contingencies [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CommitmentsAndContingenciesLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Commitments And Contingencies [Line Items]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount" xlink:type="locator" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecorded unconditional purchase obligation, total</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount" xlink:to="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceSheetAmount_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecorded Unconditional Purchase Obligation Balance Sheet Amount</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary" xlink:type="locator" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecorded unconditional purchase obligation due within four years</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary" xlink:to="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationBalanceOnFourthAnniversary_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecorded Unconditional Purchase Obligation Balance On Fourth Anniversary</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_UnrecordedUnconditionalPurchaseObligationMaximumQuantity" xlink:type="locator" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationMaximumQuantity" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationMaximumQuantity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Unrecorded unconditional purchase obligation, maximum quantity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_UnrecordedUnconditionalPurchaseObligationMaximumQuantity" xlink:to="us-gaap_UnrecordedUnconditionalPurchaseObligationMaximumQuantity_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_UnrecordedUnconditionalPurchaseObligationMaximumQuantity_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Unrecorded Unconditional Purchase Obligation Maximum Quantity</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_CostAllocationPercentage" xlink:type="locator" xlink:label="smhi_CostAllocationPercentage" />
    <link:label xml:lang="en-US" xlink:label="smhi_CostAllocationPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Cost allocation percentage.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_CostAllocationPercentage" xlink:to="smhi_CostAllocationPercentage_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_CostAllocationPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Cost allocation percentage</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CostAllocationPercentage_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cost Allocation Percentage</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:type="locator" xlink:label="us-gaap_LossContingencyEstimateOfPossibleLoss" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LossContingencyEstimateOfPossibleLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Potential range of levies</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LossContingencyEstimateOfPossibleLoss" xlink:to="us-gaap_LossContingencyEstimateOfPossibleLoss_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LossContingencyEstimateOfPossibleLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Loss Contingency Estimate Of Possible Loss</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_NumberOfCustomer" xlink:type="locator" xlink:label="smhi_NumberOfCustomer" />
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfCustomer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Number of customer.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_NumberOfCustomer" xlink:to="smhi_NumberOfCustomer_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:type="locator" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Schedule Of Segment Reporting Information By Segment [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable" xlink:to="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ScheduleOfSegmentReportingInformationBySegmentTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Schedule Of Segment Reporting Information By Segment [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByTypeAxis" xlink:type="locator" xlink:label="us-gaap_ConcentrationRiskByTypeAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Risk Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByTypeAxis" xlink:to="us-gaap_ConcentrationRiskByTypeAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskByTypeAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk By Type [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskTypeDomain" xlink:type="locator" xlink:label="us-gaap_ConcentrationRiskTypeDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Risk Type</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskTypeDomain" xlink:to="us-gaap_ConcentrationRiskTypeDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskTypeDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Type [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CustomerConcentrationRiskMember" xlink:type="locator" xlink:label="us-gaap_CustomerConcentrationRiskMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CustomerConcentrationRiskMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer Concentration Risk</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CustomerConcentrationRiskMember" xlink:to="us-gaap_CustomerConcentrationRiskMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CustomerConcentrationRiskMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Customer Concentration Risk [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GeographicConcentrationRiskMember" xlink:type="locator" xlink:label="us-gaap_GeographicConcentrationRiskMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeographicConcentrationRiskMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Geographic Concentration Risk</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GeographicConcentrationRiskMember" xlink:to="us-gaap_GeographicConcentrationRiskMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GeographicConcentrationRiskMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Geographic Concentration Risk [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:type="locator" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Risk Benchmark</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskByBenchmarkAxis" xlink:to="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskByBenchmarkAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk By Benchmark [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskBenchmarkDomain" xlink:type="locator" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration Risk Benchmark</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskBenchmarkDomain" xlink:to="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskBenchmarkDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Benchmark [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SalesRevenueNetMember" xlink:type="locator" xlink:label="us-gaap_SalesRevenueNetMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SalesRevenueNetMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Sales Revenue, Net</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SalesRevenueNetMember" xlink:to="us-gaap_SalesRevenueNetMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SalesRevenueNetMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Sales Revenue Net [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_MajorCustomersAxis" xlink:type="locator" xlink:label="srt_MajorCustomersAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_MajorCustomersAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_MajorCustomersAxis" xlink:to="srt_MajorCustomersAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_MajorCustomersAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Major Customers [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_NameOfMajorCustomerDomain" xlink:type="locator" xlink:label="srt_NameOfMajorCustomerDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_NameOfMajorCustomerDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Customer</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_NameOfMajorCustomerDomain" xlink:to="srt_NameOfMajorCustomerDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_NameOfMajorCustomerDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Name Of Major Customer [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SeacorMarineArabiaLLCMember" xlink:type="locator" xlink:label="smhi_SeacorMarineArabiaLLCMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SeacorMarineArabiaLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Seacor Marine Arabia LLC.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SeacorMarineArabiaLLCMember" xlink:to="smhi_SeacorMarineArabiaLLCMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SeacorMarineArabiaLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Seacor Marine Arabia LLC</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SeacorMarineArabiaLLCMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Seacor Marine Arabia L L C [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ZamilOffshoreMember" xlink:type="locator" xlink:label="smhi_ZamilOffshoreMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ZamilOffshoreMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Zamil Offshore.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ZamilOffshoreMember" xlink:to="smhi_ZamilOffshoreMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ZamilOffshoreMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Zamil Offshore</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ZamilOffshoreMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Zamil Offshore [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TenLargestCustomersMember" xlink:type="locator" xlink:label="smhi_TenLargestCustomersMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TenLargestCustomersMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Ten largest customers.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TenLargestCustomersMember" xlink:to="smhi_TenLargestCustomersMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TenLargestCustomersMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Ten Largest Customers</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TenLargestCustomersMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Ten Largest Customers [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_ExxonMobilMember" xlink:type="locator" xlink:label="smhi_ExxonMobilMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExxonMobilMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Exxon Mobil.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_ExxonMobilMember" xlink:to="smhi_ExxonMobilMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_ExxonMobilMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Exxon Mobil</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_ExxonMobilMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Exxon Mobil [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_SaudiAramcoMember" xlink:type="locator" xlink:label="smhi_SaudiAramcoMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_SaudiAramcoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Saudi Aramco.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_SaudiAramcoMember" xlink:to="smhi_SaudiAramcoMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_SaudiAramcoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Saudi Aramco</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_SaudiAramcoMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Saudi Aramco [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_StockholdersEquityTotalMember" xlink:type="locator" xlink:label="us-gaap_StockholdersEquityTotalMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityTotalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Stockholders&apos; Equity</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_StockholdersEquityTotalMember" xlink:to="us-gaap_StockholdersEquityTotalMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_StockholdersEquityTotalMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Stockholders Equity Total [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_NonUsMember" xlink:type="locator" xlink:label="us-gaap_NonUsMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NonUsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-US</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_NonUsMember" xlink:to="us-gaap_NonUsMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_NonUsMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Non Us [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_SegmentReportingInformationLineItems" xlink:type="locator" xlink:label="us-gaap_SegmentReportingInformationLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentReportingInformationLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Segment Reporting Information [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_SegmentReportingInformationLineItems" xlink:to="us-gaap_SegmentReportingInformationLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_SegmentReportingInformationLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Segment Reporting Information [Line Items]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_RevenueFromContractWithCustomerIncludingAssessedTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Revenue from contract with customer, including assessed tax</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_ConcentrationRiskPercentage1" xlink:type="locator" xlink:label="us-gaap_ConcentrationRiskPercentage1" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Concentration risk, percentage</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_ConcentrationRiskPercentage1" xlink:to="us-gaap_ConcentrationRiskPercentage1_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_ConcentrationRiskPercentage1_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Concentration Risk Percentage1</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfCustomer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Number of customer</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_NumberOfCustomer_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Number Of Customer</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeLossFromEquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Income (loss) from equity method investments</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense" xlink:type="locator" xlink:label="smhi_GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense" />
    <link:label xml:lang="en-US" xlink:label="smhi_GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The aggregate total of expenses of managing and administering the affairs of an entity, including affiliates of the reporting entity, including short term lease expenses, which are not directly or indirectly associated with the manufacture, sale or creation of a product or product line.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense" xlink:to="smhi_GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_AssetsExcludingCorporateAssets" xlink:type="locator" xlink:label="smhi_AssetsExcludingCorporateAssets" />
    <link:label xml:lang="en-US" xlink:label="smhi_AssetsExcludingCorporateAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">The amount of assets, excluding corporate assets.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_AssetsExcludingCorporateAssets" xlink:to="smhi_AssetsExcludingCorporateAssets_lbl" />
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductOrServiceAxis" xlink:type="locator" xlink:label="srt_ProductOrServiceAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product and Service</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductOrServiceAxis" xlink:to="srt_ProductOrServiceAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ProductOrServiceAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Product Or Service [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ProductsAndServicesDomain" xlink:type="locator" xlink:label="srt_ProductsAndServicesDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Product and Service</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ProductsAndServicesDomain" xlink:to="srt_ProductsAndServicesDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ProductsAndServicesDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Products And Services [Domain]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_TimeCharterMember" xlink:type="locator" xlink:label="smhi_TimeCharterMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_TimeCharterMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to time charter.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_TimeCharterMember" xlink:to="smhi_TimeCharterMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_TimeCharterMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Time Charter</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_TimeCharterMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Time Charter [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_BareboatCharterMember" xlink:type="locator" xlink:label="smhi_BareboatCharterMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_BareboatCharterMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to bareboat charter.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_BareboatCharterMember" xlink:to="smhi_BareboatCharterMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_BareboatCharterMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Bareboat Charter</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_BareboatCharterMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Bareboat Charter [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OtherMarineServicesMember" xlink:type="locator" xlink:label="smhi_OtherMarineServicesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherMarineServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Other marine services.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OtherMarineServicesMember" xlink:to="smhi_OtherMarineServicesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherMarineServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Marine Services</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OtherMarineServicesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Marine Services [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_PersonnelMember" xlink:type="locator" xlink:label="smhi_PersonnelMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_PersonnelMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to personnel services.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_PersonnelMember" xlink:to="smhi_PersonnelMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_PersonnelMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Personnel</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_PersonnelMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Personnel [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_RepairsAndMaintenanceMember" xlink:type="locator" xlink:label="smhi_RepairsAndMaintenanceMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_RepairsAndMaintenanceMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to repairs and maintenance services.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_RepairsAndMaintenanceMember" xlink:to="smhi_RepairsAndMaintenanceMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_RepairsAndMaintenanceMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Repairs and Maintenance</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_RepairsAndMaintenanceMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Repairs And Maintenance [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DrydockingMember" xlink:type="locator" xlink:label="smhi_DrydockingMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_DrydockingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to drydocking services.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DrydockingMember" xlink:to="smhi_DrydockingMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_DrydockingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Drydocking</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DrydockingMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Drydocking [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_InsuranceAndLossReservesMember" xlink:type="locator" xlink:label="smhi_InsuranceAndLossReservesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_InsuranceAndLossReservesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to insurance and loss reserves.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_InsuranceAndLossReservesMember" xlink:to="smhi_InsuranceAndLossReservesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_InsuranceAndLossReservesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Insurance and Loss Reserves</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_InsuranceAndLossReservesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Insurance And Loss Reserves [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_FuelLubesAndSuppliesMember" xlink:type="locator" xlink:label="smhi_FuelLubesAndSuppliesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_FuelLubesAndSuppliesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to fuel, lubes and supplies.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_FuelLubesAndSuppliesMember" xlink:to="smhi_FuelLubesAndSuppliesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_FuelLubesAndSuppliesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Fuel, Lubes and Supplies</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_FuelLubesAndSuppliesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Fuel Lubes And Supplies [Member]</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OtherDirectCostsAndExpensesMember" xlink:type="locator" xlink:label="smhi_OtherDirectCostsAndExpensesMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDirectCostsAndExpensesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Information pertaining to other direct costs and expenses.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OtherDirectCostsAndExpensesMember" xlink:to="smhi_OtherDirectCostsAndExpensesMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDirectCostsAndExpensesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Direct Costs and Expenses</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OtherDirectCostsAndExpensesMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Direct Costs And Expenses [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CostOfGoodsAndServicesSoldAndAdjustment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Direct Costs and Expenses</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_CostOfGoodsAndServicesSoldAndAdjustment_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Cost Of Goods And Services Sold And Adjustment</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_GrossProfit" xlink:type="locator" xlink:label="us-gaap_GrossProfit" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GrossProfit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Direct Vessel (Loss) Profit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_GrossProfit" xlink:to="us-gaap_GrossProfit_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_GrossProfit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Gross Profit</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Administrative and general</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">General And Administrative Expense Including Short Term Lease Expense</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_OtherCostAndExpenseOperating" xlink:type="locator" xlink:label="us-gaap_OtherCostAndExpenseOperating" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherCostAndExpenseOperating_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Costs and Expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_OtherCostAndExpenseOperating" xlink:to="us-gaap_OtherCostAndExpenseOperating_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_OtherCostAndExpenseOperating_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Cost And Expense Operating</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_GainLossOnSalesOfAssetsAndAssetImpairmentCharges_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Gains (Losses) on Asset Dispositions and Impairments, Net</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_OperatingIncomeLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating loss</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AssetsExcludingCorporateAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Total Assets</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_AssetsExcludingCorporateAssets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets Excluding Corporate Assets</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsAxis" xlink:type="locator" xlink:label="srt_ConsolidationItemsAxis" />
    <link:label xml:lang="en-US" xlink:label="srt_ConsolidationItemsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidation Items</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidationItemsAxis" xlink:to="srt_ConsolidationItemsAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ConsolidationItemsAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation Items [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd#srt_ConsolidationItemsDomain" xlink:type="locator" xlink:label="srt_ConsolidationItemsDomain" />
    <link:label xml:lang="en-US" xlink:label="srt_ConsolidationItemsDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Consolidation Items</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="srt_ConsolidationItemsDomain" xlink:to="srt_ConsolidationItemsDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="srt_ConsolidationItemsDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Consolidation Items [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_CorporateNonSegmentMember" xlink:type="locator" xlink:label="us-gaap_CorporateNonSegmentMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CorporateNonSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Corporate, Non-Segment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_CorporateNonSegmentMember" xlink:to="us-gaap_CorporateNonSegmentMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_CorporateNonSegmentMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Corporate Non Segment [Member]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_Assets_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Assets, Total</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:type="locator" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assets held for sale</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets Of Disposal Group Including Discontinued Operation</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:type="locator" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Table]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable" xlink:to="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsTable_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Table]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupClassificationAxis" xlink:type="locator" xlink:label="us-gaap_DisposalGroupClassificationAxis" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupClassificationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Disposal Group Classification</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupClassificationAxis" xlink:to="us-gaap_DisposalGroupClassificationAxis_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupClassificationAxis_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Classification [Axis]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupClassificationDomain" xlink:type="locator" xlink:label="us-gaap_DisposalGroupClassificationDomain" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupClassificationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Disposal Group Classification</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupClassificationDomain" xlink:to="us-gaap_DisposalGroupClassificationDomain_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupClassificationDomain_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Classification [Domain]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DiscontinuedOperationsHeldforsaleMember" xlink:type="locator" xlink:label="us-gaap_DiscontinuedOperationsHeldforsaleMember" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DiscontinuedOperationsHeldforsaleMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Discontinued Operations, Held-for-sale</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationsHeldforsaleMember" xlink:to="us-gaap_DiscontinuedOperationsHeldforsaleMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DiscontinuedOperationsHeldforsaleMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Discontinued Operations Heldforsale [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:type="locator" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems" xlink:to="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_IncomeStatementBalanceSheetAndAdditionalDisclosuresByDisposalGroupsIncludingDiscontinuedOperationsLineItems_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Income Statement Balance Sheet And Additional Disclosures By Disposal Groups Including Discontinued Operations [Line Items]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" xlink:type="locator" xlink:label="us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Net income from operations</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax" xlink:to="us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DiscontinuedOperationGainLossOnDisposalOfDiscontinuedOperationNetOfTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Discontinued Operation Gain Loss On Disposal Of Discontinued Operation Net Of Tax</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeEquityMethodInvestmentsAfterTax" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeEquityMethodInvestmentsAfterTax" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeEquityMethodInvestmentsAfterTax_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation income loss before equity method investments after tax.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeEquityMethodInvestmentsAfterTax" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeEquityMethodInvestmentsAfterTax_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation income (loss) from equity method investments.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeIncomeTaxesAndIncomeLossFromEquityMethodInvestments" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeIncomeTaxesAndIncomeLossFromEquityMethodInvestments" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeIncomeTaxesAndIncomeLossFromEquityMethodInvestments_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation income loss before income taxes and income loss from equity method investments.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeIncomeTaxesAndIncomeLossFromEquityMethodInvestments" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeIncomeTaxesAndIncomeLossFromEquityMethodInvestments_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpense" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpense" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation other nonoperating income expense.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpense" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpense_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationOtherNet" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNet" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation other net.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNet" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNet_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationLeaseExpense" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationLeaseExpense" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationLeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation lease expense.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationLeaseExpense" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationLeaseExpense_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationGainLossOnAssetsDispositionAndImpairmentsNet" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationGainLossOnAssetsDispositionAndImpairmentsNet" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationGainLossOnAssetsDispositionAndImpairmentsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation gain (loss) on assets disposition and impairments net.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationGainLossOnAssetsDispositionAndImpairmentsNet" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationGainLossOnAssetsDispositionAndImpairmentsNet_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_OtherRevenueMember" xlink:type="locator" xlink:label="smhi_OtherRevenueMember" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Other revenue.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_OtherRevenueMember" xlink:to="smhi_OtherRevenueMember_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_OtherRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Revenue</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_OtherRevenueMember_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Other Revenue [Member]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:type="locator" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Assets from Discontinued Operations:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:to="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Assets Of Disposal Group Including Discontinued Operation [Abstract]</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperationCurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/verboseLabel">Current assets</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Net property and equipment</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationPropertyPlantAndEquipmentNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Property Plant And Equipment Noncurrent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Non-current assets</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationAssetsNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Assets Noncurrent</link:label>
    <link:label xml:lang="en-US" xlink:label="us-gaap_AssetsOfDisposalGroupIncludingDiscontinuedOperation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Assets from discontinued operations</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:type="locator" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Liability from Discontinued Operations:</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract" xlink:to="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Of Disposal Group Including Discontinued Operation [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent" xlink:type="locator" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Long-term liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent" xlink:to="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperationNoncurrent_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Of Disposal Group Including Discontinued Operation Noncurrent</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:type="locator" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Disposal Group, Including Discontinued Operation, Liabilities</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation" xlink:to="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_LiabilitiesOfDisposalGroupIncludingDiscontinuedOperation_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Liabilities Of Disposal Group Including Discontinued Operation</link:label>
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationIncomeTaxExpenseBenefit" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeTaxExpenseBenefit" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeTaxExpenseBenefit_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation income tax expense (benefit).</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeTaxExpenseBenefit" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeTaxExpenseBenefit_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupDiscontinuedOperationOperatingRevenueAbstract" xlink:type="locator" xlink:label="smhi_DisposalGroupDiscontinuedOperationOperatingRevenueAbstract" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupDiscontinuedOperationOperatingRevenueAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group discontinued operation operating revenue.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupDiscontinuedOperationOperatingRevenueAbstract" xlink:to="smhi_DisposalGroupDiscontinuedOperationOperatingRevenueAbstract_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract" xlink:type="locator" xlink:label="smhi_DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group discontinued operation costs and expenses.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract" xlink:to="smhi_DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract_lbl" />
    <link:loc xlink:href="smhi-20211231.xsd#smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract" xlink:type="locator" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/documentation">Disposal group including discontinued operation other nonoperating income expense.</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract" xlink:to="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract_lbl" />
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupDiscontinuedOperationOperatingRevenueAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Revenues:</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupDiscontinuedOperationOperatingRevenueAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Discontinued Operation Operating Revenue [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating Revenues</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationRevenue_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Revenue</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Costs and Expenses:</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Discontinued Operation Costs And Expenses [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Operating</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Operating Expense</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationGrossProfitLoss" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationGrossProfitLoss" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationGrossProfitLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Direct Vessel Profit</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationGrossProfitLoss" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationGrossProfitLoss_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationGrossProfitLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Gross Profit Loss</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">General and Administrative Expenses</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationGeneralAndAdministrativeExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation General And Administrative Expense</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationLeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Lease Expense</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationLeaseExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Lease Expense</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Depreciation</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationDepreciationAndAmortization_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Depreciation And Amortization</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationGainLossOnAssetsDispositionAndImpairmentsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Gain on Asset Dispositions and Impairments, Net</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationGainLossOnAssetsDispositionAndImpairmentsNet_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Gain Loss On Assets Disposition And Impairments Net</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/totalLabel">Operating Income (Loss)</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationOperatingIncomeLoss_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Operating Income Loss</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Other Income (Expense)</link:label>
    <link:label xml:lang="en-US" xlink:label="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Other Nonoperating Income Expense [Abstract]</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestIncome" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestIncome" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestIncome_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Interest income</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestIncome" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestIncome_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestIncome_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Interest Income</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2009/role/negatedLabel">Interest expense</link:label>
    <link:labelArc xlink:type="arc" xlink:arcrole="http://www.xbrl.org/2003/arcrole/concept-label" xlink:from="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense" xlink:to="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense_lbl" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationInterestExpense_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/label">Disposal Group Including Discontinued Operation Interest Expense</link:label>
    <link:loc xlink:href="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd#us-gaap_DisposalGroupIncludingDiscontinuedOperationForeignCurrencyTranslationGainsLosses" xlink:type="locator" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationForeignCurrencyTranslationGainsLosses" />
    <link:label xml:lang="en-US" xlink:label="us-gaap_DisposalGroupIncludingDiscontinuedOperationForeignCurrencyTranslationGainsLosses_lbl" xlink:type="resource" xlink:role="http://www.xbrl.org/2003/role/terseLabel">Foreign currency translation (loss)</link:label>
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