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<!-- Creation Date      : 2022-11-02T06:56:33.1432836+00:00 -->
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<!-- Copyright (c) 2022 Donnelley Financial Solutions, Inc. All Rights Reserved. -->
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  <xsd:element id="smhi_BasisOfPresentationAndAccountingPoliciesAbstract" name="BasisOfPresentationAndAccountingPoliciesAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_RecentlyAdoptedAccountingStandardsPolicyTextBlock" name="RecentlyAdoptedAccountingStandardsPolicyTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_ScheduleOfGainLossOnSaleOfPropertyPlantAndEquipmentTableTextBlock" name="ScheduleOfGainLossOnSaleOfPropertyPlantAndEquipmentTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_ScheduleOfGainOnSaleOfEquityInvestmentsTableTextBlock" name="ScheduleOfGainOnSaleOfEquityInvestmentsTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_LesseeOperatingAndFinanceLeaseLiabilityMaturityTableTextBlock" name="LesseeOperatingAndFinanceLeaseLiabilityMaturityTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock" name="ScheduleOfSupplementalCashFlowInformationRelatedToLeasesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_ScheduleOfOtherInformationRelatedToLeasesTableTextBlock" name="ScheduleOfOtherInformationRelatedToLeasesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_BasisOfPresentationAndAccountingPoliciesLineItems" name="BasisOfPresentationAndAccountingPoliciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_BasisOfPresentationAndAccountingPoliciesTable" name="BasisOfPresentationAndAccountingPoliciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACORMarineForeignHoldingsMember" name="SEACORMarineForeignHoldingsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_EquityInvestmentsIn50OrLessOwnedCompaniesMember" name="EquityInvestmentsIn50OrLessOwnedCompaniesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_VesselsMember" name="VesselsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_OffshoreSupportVesselsMember" name="OffshoreSupportVesselsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_FastSupportVesselMember" name="FastSupportVesselMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_AnchorHandlingTowingSupplyVesselMember" name="AnchorHandlingTowingSupplyVesselMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_TowerAndGangwayMember" name="TowerAndGangwayMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_UnearnedRevenueRelatedToMobilizations" name="UnearnedRevenueRelatedToMobilizations" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_UnearnedRevenueRelatedToNewContractAgreements" name="UnearnedRevenueRelatedToNewContractAgreements" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_UnearnedRevenuePreviouslyRecordedRecognized" name="UnearnedRevenuePreviouslyRecordedRecognized" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_DebtInstrumentMaturityPeriod" name="DebtInstrumentMaturityPeriod" type="xbrli:gYearItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_MexMarOriginalFacilityAgreementMember" name="MexMarOriginalFacilityAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_MexMarSecondAmendedAndRestatedFacilityAgreementMember" name="MexMarSecondAmendedAndRestatedFacilityAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_MexMarThirdAmendedAndRestatedFacilityAgreementMember" name="MexMarThirdAmendedAndRestatedFacilityAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_TermLoanMember" name="TermLoanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_PaymentsToAcquirePropertyPlantAndEquipmentIncludingFairValueHedges" name="PaymentsToAcquirePropertyPlantAndEquipmentIncludingFairValueHedges" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_NumberOfEquipmentSold" name="NumberOfEquipmentSold" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_ReducedOfDebtUnderCreditFacility" name="ReducedOfDebtUnderCreditFacility" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_PropertyPlantEquipmentConsiderationTransferred" name="PropertyPlantEquipmentConsiderationTransferred" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_CapitalExpenditureAndPaymentsOnEquipment" name="CapitalExpenditureAndPaymentsOnEquipment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_PlatformSupplyVesselsMember" name="PlatformSupplyVesselsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_FastSupportVesselsMember" name="FastSupportVesselsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_LiftboatsMember" name="LiftboatsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_PlatformSupplyVesselsAndFastSupportVesselsMember" name="PlatformSupplyVesselsAndFastSupportVesselsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_FalconGlobalUSATermLoanFacilityMember" name="FalconGlobalUSATermLoanFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACORMarlinLLCMember" name="SEACORMarlinLLCMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_WindcatWorkboatsMember" name="WindcatWorkboatsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_ProceedsFromSaleOfPropertyPlantAndEquipmentGross" name="ProceedsFromSaleOfPropertyPlantAndEquipmentGross" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_PaymentsForTransactionsFeesAndOtherCosts" name="PaymentsForTransactionsFeesAndOtherCosts" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_CashSoldOnPropertyPlantAndEquipmentDisposal" name="CashSoldOnPropertyPlantAndEquipmentDisposal" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_MexMarMember" name="MexMarMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SeabulkAngolaMember" name="SeabulkAngolaMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_OffshoreVesselHoldingsMember" name="OffshoreVesselHoldingsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACORArabiaMember" name="SEACORArabiaMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_OtherOffshoreMarineServicesJointVenturesMember" name="OtherOffshoreMarineServicesJointVenturesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_OTMMember" name="OTMMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_PriorToClosingOfFrameworkAgreementMember" name="PriorToClosingOfFrameworkAgreementMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_ProceedsFromSaleOfHybridBatteryEquipment" name="ProceedsFromSaleOfHybridBatteryEquipment" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_NetProceedsFromSaleOfEquityMethodInvestments" name="NetProceedsFromSaleOfEquityMethodInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_NetEquityInJointVentures" name="NetEquityInJointVentures" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_NetBookValueOfDisposedAssets" name="NetBookValueOfDisposedAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_ConvertibleSeniorNotesMember" name="ConvertibleSeniorNotesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACORMarineForeignHoldingsCreditFacilityMember" name="SEACORMarineForeignHoldingsCreditFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SeaCatCrewzerIIITermLoanFacilityMember" name="SeaCatCrewzerIIITermLoanFacilityMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember" name="SEACOROffshoreDeltaFormerlyKnownAsSEACOSCOAcquisitionDebtMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember" name="SEACORDeltaFormerlyKnownAsSEACOSCOShipyardFinancingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACORAlpineShipyardFinancingMember" name="SEACORAlpineShipyardFinancingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACOR88888TermLoanMember" name="SEACOR88888TermLoanMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SeacorOffshoreOSVMember" name="SeacorOffshoreOSVMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_TarahumaraShipyardFinancingMember" name="TarahumaraShipyardFinancingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_ConvertibleSeniorNotesDueTwoThousandTwentyThreeMember" name="ConvertibleSeniorNotesDueTwoThousandTwentyThreeMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SeniorPIKToggleNotesDueTwoThousandTwentySixMember" name="SeniorPIKToggleNotesDueTwoThousandTwentySixMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_ConvertibleSeniorNotesDueTwoThousandTwentySixMember" name="ConvertibleSeniorNotesDueTwoThousandTwentySixMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_CashInterestMember" name="CashInterestMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_HybridInterestMember" name="HybridInterestMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_HybridInterestPaymentInKindMember" name="HybridInterestPaymentInKindMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_HybridInterestPaidInCashMember" name="HybridInterestPaidInCashMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_GuaranteedNotesMember" name="GuaranteedNotesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_CarlyleWarrantsMember" name="CarlyleWarrantsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_CarlyleGroupMember" name="CarlyleGroupMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_OtherThanCarlyleMember" name="OtherThanCarlyleMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_TrancheOneMember" name="TrancheOneMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_TrancheTwoMember" name="TrancheTwoMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_LongtermDebtObligationMember" name="LongtermDebtObligationMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_NotesRedeemableDenominationAmount" name="NotesRedeemableDenominationAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_ConvertibleNotesOutstanding" name="ConvertibleNotesOutstanding" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_DebtInstrumentConversionPricePercentage" name="DebtInstrumentConversionPricePercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_DebtInstrumentPercentageOfNewConvertibleNotesToBePurchased" name="DebtInstrumentPercentageOfNewConvertibleNotesToBePurchased" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_DebtInstrumentPercentageOfNewConvertibleNotesToBeRedeemed" name="DebtInstrumentPercentageOfNewConvertibleNotesToBeRedeemed" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_LoanPrincipalAmount" name="LoanPrincipalAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_PercentageOfLongTermDebtIncreaseInMargin" name="PercentageOfLongTermDebtIncreaseInMargin" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smhi_DebtInstrumentExtendedMaturityDate" name="DebtInstrumentExtendedMaturityDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPercentage" name="CashCashEquivalentsRestrictedCashAndRestrictedCashEquivalentsPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_PercentageOfDebtObligationsOutstanding" name="PercentageOfDebtObligationsOutstanding" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_NumberOfOperatingLeasesOnEquipment" name="NumberOfOperatingLeasesOnEquipment" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_LesseeOperatingAndFinanceLeaseTermOfContract" name="LesseeOperatingAndFinanceLeaseTermOfContract" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_NumberOfFinancingLeasesOnEquipment" name="NumberOfFinancingLeasesOnEquipment" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_OtherEquipmentMember" name="OtherEquipmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_FinanceLeaseCostsAbstract" name="FinanceLeaseCostsAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_EffectiveIncomeTaxRateReconciliationForeignWithholdingTaxAndForeignIncomeTaxNotCreditablePercent" name="EffectiveIncomeTaxRateReconciliationForeignWithholdingTaxAndForeignIncomeTaxNotCreditablePercent" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_EffectiveIncomeTaxRateReconciliationSaleOfEquityInvestments" name="EffectiveIncomeTaxRateReconciliationSaleOfEquityInvestments" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_InterestRateSwapAgreementThreePointThreeTwoPercentMember" name="InterestRateSwapAgreementThreePointThreeTwoPercentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_InterestRateSwapAgreementThreePointOneNineFivePercentMember" name="InterestRateSwapAgreementThreePointOneNineFivePercentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SEACOR88888Member" name="SEACOR88888Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_DerivativesNotionalAmount" name="DerivativesNotionalAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" />
  <xsd:element id="smhi_NumberOfPropertyAndEquipmentWithFairValue" name="NumberOfPropertyAndEquipmentWithFairValue" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_UnrecordedUnconditionalPurchaseObligationIndefinitelyDeferred" name="UnrecordedUnconditionalPurchaseObligationIndefinitelyDeferred" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_CommitmentsAndContingenciesLineItems" name="CommitmentsAndContingenciesLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_CommitmentsAndContingenciesTable" name="CommitmentsAndContingenciesTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_FSVOffshoreSupportVesselsMember" name="FSVOffshoreSupportVesselsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_DeficiencyNoticeMember" name="DeficiencyNoticeMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SeabulkOverseasMember" name="SeabulkOverseasMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_CostAllocationPercentage" name="CostAllocationPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" />
  <xsd:element id="smhi_GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense" name="GeneralAndAdministrativeExpenseIncludingShortTermLeaseExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_AfricaAndEuropeMember" name="AfricaAndEuropeMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_MiddleEastAndAsiaMember" name="MiddleEastAndAsiaMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_TimeCharterMember" name="TimeCharterMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_BareboatCharterMember" name="BareboatCharterMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_OtherMarineServicesMember" name="OtherMarineServicesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_PersonnelMember" name="PersonnelMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_RepairsAndMaintenanceMember" name="RepairsAndMaintenanceMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_DrydockingMember" name="DrydockingMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_InsuranceAndLossReservesMember" name="InsuranceAndLossReservesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_FuelLubesAndSuppliesMember" name="FuelLubesAndSuppliesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_OtherDirectCostsAndExpensesMember" name="OtherDirectCostsAndExpensesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_AssetsExcludingCorporateAssets" name="AssetsExcludingCorporateAssets" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_EquityInEarningsLossesOfOwnedCompanies" name="EquityInEarningsLossesOfOwnedCompanies" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_SegmentInformationLineItems" name="SegmentInformationLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_SegmentInformationTable" name="SegmentInformationTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_WindcatWorkboatsLtdMember" name="WindcatWorkboatsLtdMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_DisposalGroupIncludingDiscontinuedOperationLeaseExpense" name="DisposalGroupIncludingDiscontinuedOperationLeaseExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_DisposalGroupIncludingDiscontinuedOperationExpenses" name="DisposalGroupIncludingDiscontinuedOperationExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpense" name="DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpense" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeIncomeTaxesAndIncomeLossFromEquityMethodInvestments" name="DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeIncomeTaxesAndIncomeLossFromEquityMethodInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeTaxExpenseBenefit" name="DisposalGroupIncludingDiscontinuedOperationIncomeTaxExpenseBenefit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="debit" />
  <xsd:element id="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeEquityMethodInvestmentsAfterTax" name="DisposalGroupIncludingDiscontinuedOperationIncomeLossBeforeEquityMethodInvestmentsAfterTax" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments" name="DisposalGroupIncludingDiscontinuedOperationIncomeLossFromEquityMethodInvestments" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="false" xbrli:balance="credit" />
  <xsd:element id="smhi_DisposalGroupDiscontinuedOperationOperatingRevenueAbstract" name="DisposalGroupDiscontinuedOperationOperatingRevenueAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract" name="DisposalGroupDiscontinuedOperationCostsAndExpensesAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract" name="DisposalGroupIncludingDiscontinuedOperationOtherNonoperatingIncomeExpenseAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
  <xsd:element id="smhi_OtherRevenueMember" name="OtherRevenueMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" nillable="true" abstract="true" />
</xsd:schema>
