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      <link:roleType roleURI="http://castormaritime.com/role/CostOfRevenueFromServicesTables" id="CostOfRevenueFromServicesTables">
        <!--Parent Role: Cost of revenue from services-->
        <link:definition>082200 - Disclosure - Cost of revenue from services (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/InterestAndFinanceCostsTables" id="InterestAndFinanceCostsTables">
        <!--Parent Role: Interest and Finance Costs-->
        <link:definition>082300 - Disclosure - Interest and Finance Costs (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/IncomeTaxesTables" id="IncomeTaxesTables">
        <!--Parent Role: Income Taxes-->
        <link:definition>082400 - Disclosure - Income Taxes (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/SharebasedCompensationTables" id="SharebasedCompensationTables">
        <!--Parent Role: Share-based compensation-->
        <link:definition>082500 - Disclosure - Share-based compensation (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/SegmentInformationTables" id="SegmentInformationTables">
        <!--Parent Role: Segment Information-->
        <link:definition>082600 - Disclosure - Segment Information (Tables)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/BasisOfPresentationAndGeneralInformationGeneralInformationDetails" id="BasisOfPresentationAndGeneralInformationGeneralInformationDetails">
        <!--Parent Role: Basis of Presentation and General information-->
        <link:definition>090100 - Disclosure - Basis of Presentation and General information, General Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/TransactionsWithRelatedPartiesSummaryDetails" id="TransactionsWithRelatedPartiesSummaryDetails">
        <!--Parent Role: Transactions with Related Parties-->
        <link:definition>090300 - Disclosure - Transactions with Related Parties, Summary (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/TransactionsWithRelatedPartiesCastorShipsDetails" id="TransactionsWithRelatedPartiesCastorShipsDetails">
        <!--Parent Role: Transactions with Related Parties-->
        <link:definition>090302 - Disclosure - Transactions with Related Parties, Castor Ships (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/TransactionsWithRelatedPartiesPavimarDetails" id="TransactionsWithRelatedPartiesPavimarDetails">
        <!--Parent Role: Transactions with Related Parties-->
        <link:definition>090304 - Disclosure - Transactions with Related Parties, Pavimar (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/TransactionsWithRelatedPartiesInvestmentInRelatedPartyDetails" id="TransactionsWithRelatedPartiesInvestmentInRelatedPartyDetails">
        <!--Parent Role: Transactions with Related Parties-->
        <link:definition>090306 - Disclosure - Transactions with Related Parties, Investment in Related Party (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/TransactionsWithRelatedPartiesIssuanceOfSeriesDPreferredSharesToToroDetails" id="TransactionsWithRelatedPartiesIssuanceOfSeriesDPreferredSharesToToroDetails">
        <!--Parent Role: Transactions with Related Parties-->
        <link:definition>090308 - Disclosure - Transactions with Related Parties, Issuance of Series D Preferred shares to Toro (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/TransactionsWithRelatedPartiesLongtermDebtRelatedPartyDetails" id="TransactionsWithRelatedPartiesLongtermDebtRelatedPartyDetails">
        <!--Parent Role: Transactions with Related Parties-->
        <link:definition>090310 - Disclosure - Transactions with Related Parties, Long-Term Debt, Related Party (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/TransactionsWithRelatedPartiesMpcCapitalRelatedPartiesDetails" id="TransactionsWithRelatedPartiesMpcCapitalRelatedPartiesDetails">
        <!--Parent Role: Transactions with Related Parties-->
        <link:definition>090314 - Disclosure - Transactions with Related Parties, MPC Capital Related Parties (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/DeferredChargesNetDetails" id="DeferredChargesNetDetails">
        <!--Parent Role: Deferred Charges, net-->
        <link:definition>090400 - Disclosure - Deferred Charges, net (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/FairValueOfAcquiredTimeChartersDetails" id="FairValueOfAcquiredTimeChartersDetails">
        <!--Parent Role: Fair Value of Acquired Time Charters-->
        <link:definition>090500 - Disclosure - Fair Value of Acquired Time Charters (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/VesselsNetNetBookValueDetails" id="VesselsNetNetBookValueDetails">
        <!--Parent Role: Vessels, net-->
        <link:definition>090600 - Disclosure - Vessels, net, Net Book Value (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/VesselsNetVesselAcquisitionsAndOtherCapitalExpendituresDetails" id="VesselsNetVesselAcquisitionsAndOtherCapitalExpendituresDetails">
        <!--Parent Role: Vessels, net-->
        <link:definition>090602 - Disclosure - Vessels, net, Vessel Acquisitions and other Capital Expenditures (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/PropertyPlantAndEquipmentNetPropertyAndEquipmentByMajorAssetClassesDetails" id="PropertyPlantAndEquipmentNetPropertyAndEquipmentByMajorAssetClassesDetails">
        <!--Parent Role: Property, Plant and Equipment, net-->
        <link:definition>090700 - Disclosure - Property, Plant and Equipment, net, Property and Equipment by Major Asset Classes (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/PropertyPlantAndEquipmentNetGrossCarryingAmountAndAccumulatedDepreciationDetails" id="PropertyPlantAndEquipmentNetGrossCarryingAmountAndAccumulatedDepreciationDetails">
        <!--Parent Role: Property, Plant and Equipment, net-->
        <link:definition>090704 - Disclosure - Property, Plant and Equipment, net, Gross Carrying Amount and Accumulated Depreciation (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/IntangibleAssetsNetDetails" id="IntangibleAssetsNetDetails">
        <!--Parent Role: Intangible Assets, net-->
        <link:definition>090800 - Disclosure - Intangible Assets, net (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/GoodwillDetails" id="GoodwillDetails">
        <!--Parent Role: Goodwill-->
        <link:definition>090900 - Disclosure - Goodwill (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/EquityMethodInvestmentsOwnershipInterestsAndCarryingAmountDetails" id="EquityMethodInvestmentsOwnershipInterestsAndCarryingAmountDetails">
        <!--Parent Role: Equity Method Investments-->
        <link:definition>091000 - Disclosure - Equity Method Investments, Ownership Interests and Carrying Amount (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/EquityMethodInvestmentsEquityMethodInvestmentsDevelopedDetails" id="EquityMethodInvestmentsEquityMethodInvestmentsDevelopedDetails">
        <!--Parent Role: Equity Method Investments-->
        <link:definition>091002 - Disclosure - Equity method investments, Equity Method Investments Developed (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/EquityMethodInvestmentsEquityMethodInvestmentsMeasuredAtFairValueDetails" id="EquityMethodInvestmentsEquityMethodInvestmentsMeasuredAtFairValueDetails">
        <!--Parent Role: Equity Method Investments-->
        <link:definition>091004 - Disclosure - Equity Method Investments, Equity Method Investments Measured at Fair Value (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/EquityMethodInvestmentsSummarizedConsolidatedFinancialInformationDetails" id="EquityMethodInvestmentsSummarizedConsolidatedFinancialInformationDetails">
        <!--Parent Role: Equity Method Investments-->
        <link:definition>091006 - Disclosure - Equity Method Investments, Summarized Consolidated Financial Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/EquityMethodInvestmentsFairValuesOfAssetsAcquiredAndLiabilitiesAssumedDetails" id="EquityMethodInvestmentsFairValuesOfAssetsAcquiredAndLiabilitiesAssumedDetails">
        <!--Parent Role: Equity Method Investments-->
        <link:definition>091008 - Disclosure - Equity Method Investments, Fair Values of the Assets Acquired and Liabilities Assumed (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LongtermDebtLongtermDebtDetails" id="LongtermDebtLongtermDebtDetails">
        <!--Parent Role: Long-Term Debt-->
        <link:definition>091100 - Disclosure - Long-Term Debt, Long-Term Debt (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LongtermDebt500MillionTermLoanFacilityDetails" id="LongtermDebt500MillionTermLoanFacilityDetails">
        <!--Parent Role: Long-Term Debt-->
        <link:definition>091102 - Disclosure - Long-Term Debt, $50.0 Million Term Loan Facility (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LongtermDebtAnnualPrincipalPaymentsDetails" id="LongtermDebtAnnualPrincipalPaymentsDetails">
        <!--Parent Role: Long-Term Debt-->
        <link:definition>091106 - Disclosure - Long-Term Debt, Annual Principal Payments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LongtermDebtAndFinancialLiabilitiesFinancialLiabilitiesDetails" id="LongtermDebtAndFinancialLiabilitiesFinancialLiabilitiesDetails">
        <!--Parent Role: Long-Term Debt-->
        <link:definition>091108 - Disclosure - Long-Term Debt and Financial Liabilities, Financial Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LongtermDebtSaleAndLeasebackAgreementsDetails" id="LongtermDebtSaleAndLeasebackAgreementsDetails">
        <!--Parent Role: Long-Term Debt-->
        <link:definition>091110 - Disclosure - Long-Term Debt, Sale and Leaseback Agreements (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LongtermDebtAndFinancialLiabilitiesAnnualFinancialLiabilitiesDetails" id="LongtermDebtAndFinancialLiabilitiesAnnualFinancialLiabilitiesDetails">
        <!--Parent Role: Long-Term Debt-->
        <link:definition>091112 - Disclosure - Long-Term Debt and Financial Liabilities, Annual Financial Liabilities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
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      <link:roleType roleURI="http://castormaritime.com/role/InvestmentInEquitySecuritiesEquityInvestmentsDetails" id="InvestmentInEquitySecuritiesEquityInvestmentsDetails">
        <!--Parent Role: Investment in equity securities/ Equity Investments-->
        <link:definition>091200 - Disclosure - Investment in equity securities/ Equity Investments (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/InvestmentInDebtSecuritiesHeldToMaturityInvestmentInDebtSecuritiesDetails" id="InvestmentInDebtSecuritiesHeldToMaturityInvestmentInDebtSecuritiesDetails">
        <!--Parent Role: Investment in debt securities-->
        <link:definition>091300 - Disclosure - Investment in debt securities, Held to Maturity Investment in Debt Securities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/InvestmentInDebtSecuritiesCarryingAmountAndUnrealizedGainsOfTradingDebtSecuritiesDetails" id="InvestmentInDebtSecuritiesCarryingAmountAndUnrealizedGainsOfTradingDebtSecuritiesDetails">
        <!--Parent Role: Investment in debt securities-->
        <link:definition>091302 - Disclosure - Investment in debt securities, Carrying Amount and Unrealized Gains of Trading Debt Securities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/EquityCapitalStructureCapitalStockDetails" id="EquityCapitalStructureCapitalStockDetails">
        <!--Parent Role: Equity Capital Structure-->
        <link:definition>091400 - Disclosure - Equity Capital Structure, Capital Stock (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/EquityCapitalStructureSeriesDCumulativePerpetualConvertiblePreferredSharesDetails" id="EquityCapitalStructureSeriesDCumulativePerpetualConvertiblePreferredSharesDetails">
        <!--Parent Role: Equity Capital Structure-->
        <link:definition>091404 - Disclosure - Equity Capital Structure, Series D Cumulative Perpetual Convertible Preferred Shares (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/FinancialInstrumentsAndFairValueDisclosuresInvestmentInDebtSecuritiesDetails" id="FinancialInstrumentsAndFairValueDisclosuresInvestmentInDebtSecuritiesDetails">
        <!--Parent Role: Financial Instruments and Fair Value Disclosures-->
        <link:definition>091500 - Disclosure - Financial Instruments and Fair Value Disclosures, Investment in Debt Securities (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/FinancialInstrumentsAndFairValueDisclosuresDerivativeContractsMeasuredOnRecurringBasisDetails" id="FinancialInstrumentsAndFairValueDisclosuresDerivativeContractsMeasuredOnRecurringBasisDetails">
        <!--Parent Role: Financial Instruments and Fair Value Disclosures-->
        <link:definition>091502 - Disclosure - Financial Instruments and Fair Value Disclosures, Derivative Contracts Measured on Recurring Basis (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/FinancialInstrumentsAndFairValueDisclosuresRealizedAndUnrealizedGainsAndLossesDetails" id="FinancialInstrumentsAndFairValueDisclosuresRealizedAndUnrealizedGainsAndLossesDetails">
        <!--Parent Role: Financial Instruments and Fair Value Disclosures-->
        <link:definition>091504 - Disclosure - Financial Instruments and Fair Value Disclosures, Realized and Unrealized Gains and Losses (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LeasesLeaseCostDetails" id="LeasesLeaseCostDetails">
        <!--Parent Role: Leases-->
        <link:definition>091600 - Disclosure - Leases, Lease Cost (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LeasesOtherInformationDetails" id="LeasesOtherInformationDetails">
        <!--Parent Role: Leases-->
        <link:definition>091602 - Disclosure - Leases, Other Information (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LeasesUndiscountedCashFlowsOfLeaseLiabilityDetails" id="LeasesUndiscountedCashFlowsOfLeaseLiabilityDetails">
        <!--Parent Role: Leases-->
        <link:definition>091604 - Disclosure - Leases, Undiscounted Cash Flows of Lease Liability (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/LeasesUndiscountedCashFlowsOfLeaseLiabilityDetailsCalc01" id="LeasesUndiscountedCashFlowsOfLeaseLiabilityDetailsCalc01">
        <!--Parent Role: Leases, Undiscounted Cash Flows of Lease Liability (Details)-->
        <link:definition>091606 - Disclosure - Leases, Undiscounted Cash Flows of Lease Liability (Details) CALC 01</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/CommitmentsAndContingenciesCommitmentsUnderLongtermLeaseContractsDetails" id="CommitmentsAndContingenciesCommitmentsUnderLongtermLeaseContractsDetails">
        <!--Parent Role: Commitments and Contingencies-->
        <link:definition>091700 - Disclosure - Commitments and Contingencies, Commitments Under Long-Term Lease Contracts (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/CommitmentsAndContingenciesContingenciesDetails" id="CommitmentsAndContingenciesContingenciesDetails">
        <!--Parent Role: Commitments and Contingencies-->
        <link:definition>091702 - Disclosure - Commitments and Contingencies, Contingencies (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/EarningsPerCommonShareDetails" id="EarningsPerCommonShareDetails">
        <!--Parent Role: Earnings Per Common Share-->
        <link:definition>091800 - Disclosure - Earnings Per Common Share (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/RevenuesVesselRevenuesDetails" id="RevenuesVesselRevenuesDetails">
        <!--Parent Role: Revenues-->
        <link:definition>091900 - Disclosure - Revenues, Vessel Revenues (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/RevenuesRevenueFromServicesDetails" id="RevenuesRevenueFromServicesDetails">
        <!--Parent Role: Revenues-->
        <link:definition>091902 - Disclosure - Revenues, Revenue from Services (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:roleType roleURI="http://castormaritime.com/role/VesselOperatingExpensesAndVoyageExpensesDetails" id="VesselOperatingExpensesAndVoyageExpensesDetails">
        <!--Parent Role: Vessel Operating Expenses and Voyage Expenses-->
        <link:definition>092000 - Disclosure - Vessel Operating Expenses and Voyage Expenses (Details)</link:definition>
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        <link:usedOn>link:calculationLink</link:usedOn>
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  <xs:element name="InterestAndFinanceCostsLineItems" id="ctrm_InterestAndFinanceCostsLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="ContainershipSegmentMember" id="ctrm_ContainershipSegmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="DryBulkSegmentMember" id="ctrm_DryBulkSegmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="AssetManagementSegmentMember" id="ctrm_AssetManagementSegmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="SeniorTermLoanFacilityAlphaBankSAMember" id="ctrm_SeniorTermLoanFacilityAlphaBankSAMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="NumberOfSubsidiariesProvidingSecurityForTermLoanFacility" id="ctrm_NumberOfSubsidiariesProvidingSecurityForTermLoanFacility" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" />
  <xs:element name="CapitalizedContractCostAdditions" id="ctrm_CapitalizedContractCostAdditions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="NumberOfVesselsCompletingScheduledDrydockingRepairs" id="ctrm_NumberOfVesselsCompletingScheduledDrydockingRepairs" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="DryBulkCarrierMember" id="ctrm_DryBulkCarrierMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="InvestmentInRelatedPartyAbstract" id="ctrm_InvestmentInRelatedPartyAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="DividendMultiplierFactor" id="ctrm_DividendMultiplierFactor" type="xbrli:pureItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="PreferredStockVotingRightsNumberOfVotes" id="ctrm_PreferredStockVotingRightsNumberOfVotes" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="PreferredStockStatedValuePerShare" id="ctrm_PreferredStockStatedValuePerShare" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" />
  <xs:element name="PercentageOfVolumeWeightedAveragePrice" id="ctrm_PercentageOfVolumeWeightedAveragePrice" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="NumberOfConsecutiveTradingDayCommencingOnDistributionDate" id="ctrm_NumberOfConsecutiveTradingDayCommencingOnDistributionDate" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="NumberOfConsecutiveTradingDayExpiringOnTradingDay" id="ctrm_NumberOfConsecutiveTradingDayExpiringOnTradingDay" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="ToroCorpMember" id="ctrm_ToroCorpMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="ScheduleOfFinancialLiabilitiesTableTextBlock" id="ctrm_ScheduleOfFinancialLiabilitiesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="CostOfRevenueFromServicesTextBlock" id="ctrm_CostOfRevenueFromServicesTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="CostOtherExpenses" id="ctrm_CostOtherExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="CommissionsToRelatedParty" id="ctrm_CommissionsToRelatedParty" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="CostOfCommissions" id="ctrm_CostOfCommissions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="CostOfPurchasedServices" id="ctrm_CostOfPurchasedServices" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="CostOfRevenueFromServicesTableTextBlock" id="ctrm_CostOfRevenueFromServicesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="NumberOfVesselsMortgagedAsCollateral" id="ctrm_NumberOfVesselsMortgagedAsCollateral" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" />
  <xs:element name="NumberOfShipOwningSubsidiariesEnteringIntoTermLoanFacility" id="ctrm_NumberOfShipOwningSubsidiariesEnteringIntoTermLoanFacility" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" />
  <xs:element name="DebtInstrumentNumberOfConsecutivePaymentInstallments" id="ctrm_DebtInstrumentNumberOfConsecutivePaymentInstallments" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="EquitySecuritiesFVNIDividendIncome" id="ctrm_EquitySecuritiesFVNIDividendIncome" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" />
  <xs:element name="MPCEuropeanCleanEnergySAMember" id="ctrm_MPCEuropeanCleanEnergySAMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="MPCOSEOffshoreKSMember" id="ctrm_MPCOSEOffshoreKSMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="EquitySecuritiesWithoutReadilyDeterminableFairValueTransfers" id="ctrm_EquitySecuritiesWithoutReadilyDeterminableFairValueTransfers" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="EquityMethodInvestmentPercentageOfIncreaseInEquityInvestment" id="ctrm_EquityMethodInvestmentPercentageOfIncreaseInEquityInvestment" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="EquitySecuritiesWithoutReadilyDeterminableFairValueDividendIncome" id="ctrm_EquitySecuritiesWithoutReadilyDeterminableFairValueDividendIncome" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" />
  <xs:element name="EquityMethodInvestmentDistributionReceived" id="ctrm_EquityMethodInvestmentDistributionReceived" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="EquitySecuritiesWithoutReadilyDeterminableFairValuePurchased" id="ctrm_EquitySecuritiesWithoutReadilyDeterminableFairValuePurchased" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLoss" id="ctrm_EquitySecuritiesWithoutReadilyDeterminableFairValueImpairmentLoss" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="MPCMnchmeyerPetersenITServicesGmbHMember" id="ctrm_MPCMnchmeyerPetersenITServicesGmbHMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
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  <xs:element name="EquitySecuritiesWithoutReadilyDeterminableFairValueUnrealizedForeignExchangeGainLoss" id="ctrm_EquitySecuritiesWithoutReadilyDeterminableFairValueUnrealizedForeignExchangeGainLoss" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" />
  <xs:element name="EquitySecuritiesWithoutReadilyDeterminableFairValueProceedsFromSaleOfEquitySecurities" id="ctrm_EquitySecuritiesWithoutReadilyDeterminableFairValueProceedsFromSaleOfEquitySecurities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" />
  <xs:element name="RelatedPartyTransactionFixedDailyFee" id="ctrm_RelatedPartyTransactionFixedDailyFee" type="srt-types:perUnitItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="TechnicalShipmanagementAgreementsMember" id="ctrm_TechnicalShipmanagementAgreementsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="PavimarSAMember" id="ctrm_PavimarSAMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
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  <xs:element name="FinancialLiabilitiesGrossNoncurrent" id="ctrm_FinancialLiabilitiesGrossNoncurrent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" />
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  <xs:element name="FinancialLiabilitiesCarryingAmount" id="ctrm_FinancialLiabilitiesCarryingAmount" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" />
  <xs:element name="DeferredFinancingLiabilitiesCostsNet" id="ctrm_DeferredFinancingLiabilitiesCostsNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" />
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  <xs:element name="DeferredFinanceCostsNoncurrentNetFinancialLiabilities" id="ctrm_DeferredFinanceCostsNoncurrentNetFinancialLiabilities" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" xbrli:balance="debit" />
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  <xs:element name="EffectOnSubsidiaryShareBasedExpensesDilutedEarningsPerShare" id="ctrm_EffectOnSubsidiaryShareBasedExpensesDilutedEarningsPerShare" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="credit" />
  <xs:element name="FinanceLeaseLiabilityToBePaidAfterRollingYearFiveAndThereafter" id="ctrm_FinanceLeaseLiabilityToBePaidAfterRollingYearFiveAndThereafter" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" />
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  <xs:element name="WindFarmProductionCapacity" id="ctrm_WindFarmProductionCapacity" type="xbrli:decimalItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" />
  <xs:element name="RelatedPartyTransactionFlatManagementFees" id="ctrm_RelatedPartyTransactionFlatManagementFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="CastorShipManagementAgreementsMember" id="ctrm_CastorShipManagementAgreementsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="HarperPetersenHamburgMember" id="ctrm_HarperPetersenHamburgMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="OperatingExpensesPaymentsMember" id="ctrm_OperatingExpensesPaymentsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="NumberOfVesselsSold" id="ctrm_NumberOfVesselsSold" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="RelatedPartyTransactionSaleAndPurchaseCommissions" id="ctrm_RelatedPartyTransactionSaleAndPurchaseCommissions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="WorkingCapitalGuaranteeAdvancesMember" id="ctrm_WorkingCapitalGuaranteeAdvancesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="AmendedCastorShipManagementAgreementsMember" id="ctrm_AmendedCastorShipManagementAgreementsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="CastorShipsSAMember" id="ctrm_CastorShipsSAMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="PanamaxVesselMember" id="ctrm_PanamaxVesselMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="ContainerVesselMember" id="ctrm_ContainerVesselMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="FundingPeriodForAdvanceToCoverVesselDailyOperatingCosts" id="ctrm_FundingPeriodForAdvanceToCoverVesselDailyOperatingCosts" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="DeferredLoanFeesMember" id="ctrm_DeferredLoanFeesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="GoodwillAbstract" id="ctrm_GoodwillAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="PersonnelExpenses" id="ctrm_PersonnelExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="OfficeAndTechnologyExpensesIncludingRent" id="ctrm_OfficeAndTechnologyExpensesIncludingRent" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="AuditFees" id="ctrm_AuditFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="DirectorFees" id="ctrm_DirectorFees" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="GeneralAndAdministrativeExpensesTableTextBlock" id="ctrm_GeneralAndAdministrativeExpensesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="GrossTransportationIncomeTax" id="ctrm_GrossTransportationIncomeTax" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="IncomeTaxDisclosureTable" id="ctrm_IncomeTaxDisclosureTable" type="xbrli:stringItemType" substitutionGroup="xbrldt:hypercubeItem" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="IncomeTaxDisclosureLineItems" id="ctrm_IncomeTaxDisclosureLineItems" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="OtherTaxesPayable" id="ctrm_OtherTaxesPayable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" />
  <xs:element name="TradeTaxesPayable" id="ctrm_TradeTaxesPayable" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" />
  <xs:element name="CorporateIncomeTax" id="ctrm_CorporateIncomeTax" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" xbrli:balance="credit" />
  <xs:element name="MPCMunchmeyerPetersenCapitalAGMember" id="ctrm_MPCMunchmeyerPetersenCapitalAGMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="DebtSecuritiesFairValueDisclosureTableTextBlock" id="ctrm_DebtSecuritiesFairValueDisclosureTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="ScheduleOfRealizedAndUnrealizedGainLossOnDerivativesTableTextBlock" id="ctrm_ScheduleOfRealizedAndUnrealizedGainLossOnDerivativesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="ScheduleOfProvisionForIncomeTaxesTableTextBlock" id="ctrm_ScheduleOfProvisionForIncomeTaxesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="ScheduleOfRevenuesFromServicesWithRelatedPartiesTableTextBlock" id="ctrm_ScheduleOfRevenuesFromServicesWithRelatedPartiesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="RelatedPartyTransactionDueFromToRelatedPartiesAbstract" id="ctrm_RelatedPartyTransactionDueFromToRelatedPartiesAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="WindTurbinesMember" id="ctrm_WindTurbinesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="EnergieparkHeringenPhilippsthalWPHPGmbHCoKGMember" id="ctrm_EnergieparkHeringenPhilippsthalWPHPGmbHCoKGMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="NumberOfWindTurbineGenerators" id="ctrm_NumberOfWindTurbineGenerators" type="xbrli:integerItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="instant" />
  <xs:element name="VesselOperatingExpensesAndVoyageExpensesAbstract" id="ctrm_VesselOperatingExpensesAndVoyageExpensesAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="VesselOperatingAndVoyageExpensesTextBlock" id="ctrm_VesselOperatingAndVoyageExpensesTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
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  <xs:element name="VesselOperatingExpensesTableTextBlock" id="ctrm_VesselOperatingExpensesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" />
  <xs:element name="VoyageExpenseAbstract" id="ctrm_VoyageExpenseAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" nillable="true" abstract="true" xbrli:periodType="duration" />
  <xs:element name="BrokerageCommissions" id="ctrm_BrokerageCommissions" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="PortAndOtherExpenses" id="ctrm_PortAndOtherExpenses" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
  <xs:element name="LossGainOnBunkerFuel" id="ctrm_LossGainOnBunkerFuel" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" abstract="false" xbrli:periodType="duration" xbrli:balance="debit" />
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</xs:schema>
