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<element name="CorporateOfficeSpaceMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_CorporateOfficeSpaceMember" substitutionGroup="xbrli:item" />
<element name="NoteFourEpsilonMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteFourEpsilonMember" substitutionGroup="xbrli:item" />
<element name="NoteOneMonacoTwoThousandFourteenMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteOneMonacoTwoThousandFourteenMember" substitutionGroup="xbrli:item" />
<element name="NoteSeveMinosaTwoThousandEighteenMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteSeveMinosaTwoThousandEighteenMember" substitutionGroup="xbrli:item" />
<element name="NoteSixMinosaTwoMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteSixMinosaTwoMember" substitutionGroup="xbrli:item" />
<element name="NoteThreeMinosaOneMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteThreeMinosaOneMember" substitutionGroup="xbrli:item" />
<element name="Note9LitigationFinancingMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_Note9LitigationFinancingMember" substitutionGroup="xbrli:item" />
<element name="NoteTenPayrollProtectionProgramMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteTenPayrollProtectionProgramMember" substitutionGroup="xbrli:item" />
<element name="NoteElevenEmergencyInjuryDisasterLoanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteElevenEmergencyInjuryDisasterLoanMember" substitutionGroup="xbrli:item" />
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<element name="NoteFiveSmomMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteFiveSmomMember" substitutionGroup="xbrli:item" />
<element name="NoteTwoMonacoTwoThousandSixteenMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteTwoMonacoTwoThousandSixteenMember" substitutionGroup="xbrli:item" />
<element name="NoteTwelveVendorNotePayableMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_NoteTwelveVendorNotePayableMember" substitutionGroup="xbrli:item" />
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<element name="NotesCeasedToBearInterestAmount" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_NotesCeasedToBearInterestAmount" substitutionGroup="xbrli:item" xbrli:balance="debit" />
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<element name="LoanModificationMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_LoanModificationMember" substitutionGroup="xbrli:item" />
<element name="ExploracionesOceanicasMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_ExploracionesOceanicasMember" substitutionGroup="xbrli:item" />
<element name="OceanicaMarineOperationsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_OceanicaMarineOperationsMember" substitutionGroup="xbrli:item" />
<element name="MarineVesselMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_MarineVesselMember" substitutionGroup="xbrli:item" />
<element name="DeferredRevenueCallOptionMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_DeferredRevenueCallOptionMember" substitutionGroup="xbrli:item" />
<element name="EstimatedMarketRateLoanPercentage" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_EstimatedMarketRateLoanPercentage" substitutionGroup="xbrli:item" />
<element name="InvestmentsOptionsExpirationDate" type="xbrli:dateItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_InvestmentsOptionsExpirationDate" substitutionGroup="xbrli:item" />
<element name="DebtInstrumentNumberOfAdvances" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_DebtInstrumentNumberOfAdvances" substitutionGroup="xbrli:item" />
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<element name="TwoThousandAndFourteenConvertiblePromissoryNotesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_TwoThousandAndFourteenConvertiblePromissoryNotesMember" substitutionGroup="xbrli:item" />
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<element name="TrancheFourMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_TrancheFourMember" substitutionGroup="xbrli:item" />
<element name="TrancheMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_TrancheMember" substitutionGroup="xbrli:item" />
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<element name="WarrantExpireDate" type="xbrli:dateItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_WarrantExpireDate" substitutionGroup="xbrli:item" />
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<element name="PoplarFallsLlcMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_PoplarFallsLlcMember" substitutionGroup="xbrli:item" />
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<element name="LitigationFinancingMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_LitigationFinancingMember" substitutionGroup="xbrli:item" />
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<element name="PercentOfLoanThatWillForgiven" type="num:percentItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="omex_PercentOfLoanThatWillForgiven" substitutionGroup="xbrli:item" />
<element name="CaresActLoanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_CaresActLoanMember" substitutionGroup="xbrli:item" />
<element name="EmergencyInjuryDisasterLoanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_EmergencyInjuryDisasterLoanMember" substitutionGroup="xbrli:item" />
<element name="CollateralAgreementMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_CollateralAgreementMember" substitutionGroup="xbrli:item" />
<element name="MagellanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_MagellanMember" substitutionGroup="xbrli:item" />
<element name="CollateralAssetCarryingValue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="omex_CollateralAssetCarryingValue" substitutionGroup="xbrli:item" xbrli:balance="debit" />
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<element name="IncentiveStockOptionsMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_IncentiveStockOptionsMember" substitutionGroup="xbrli:item" />
<element name="TwoThousandFifteenStockIncentivePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_TwoThousandFifteenStockIncentivePlanMember" substitutionGroup="xbrli:item" />
<element name="TwoThousandNineteenStockIncentivePlanMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_TwoThousandNineteenStockIncentivePlanMember" substitutionGroup="xbrli:item" />
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<element name="EligibleEmployeeThresholdPercentage" type="num:percentItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_EligibleEmployeeThresholdPercentage" substitutionGroup="xbrli:item" />
<element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumAmountPayableInCashPerEmployee" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_ShareBasedCompensationArrangementByShareBasedPaymentAwardMaximumAmountPayableInCashPerEmployee" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisePriceCondition" type="xbrli:stringItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_ShareBasedCompensationArrangementByShareBasedPaymentAwardExercisePriceCondition" substitutionGroup="xbrli:item" />
<element name="ClassOfWarrantOrRightExpirationDate" type="xbrli:dateItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_ClassOfWarrantOrRightExpirationDate" substitutionGroup="xbrli:item" />
<element name="PurchasePriceOfWarrant" type="num:perShareItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="omex_PurchasePriceOfWarrant" substitutionGroup="xbrli:item" />
<element name="AmountWithHeldToPayTheOfferingCostsAtALaterDate" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="omex_AmountWithHeldToPayTheOfferingCostsAtALaterDate" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="AmendmentAxis" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_AmendmentAxis" substitutionGroup="xbrldt:dimensionItem" />
<element name="AmendmentDomain" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_AmendmentDomain" substitutionGroup="xbrli:item" />
<element name="SecondAmendmentAgreementMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_SecondAmendmentAgreementMember" substitutionGroup="xbrli:item" />
<element name="SeriesAaTwoConvertiblePreferredStockMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_SeriesAaTwoConvertiblePreferredStockMember" substitutionGroup="xbrli:item" />
<element name="SeriesAaOneConvertiblePreferredStockMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_SeriesAaOneConvertiblePreferredStockMember" substitutionGroup="xbrli:item" />
<element name="SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_SharebasedCompensationArrangementBySharebasedPaymentAwardOptionsOutstandingWeightedAverageExercisePriceAndAdditionalDisclosuresAbstract" substitutionGroup="xbrli:item" />
<element name="PreferredStockTable" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_PreferredStockTable" substitutionGroup="xbrldt:hypercubeItem" />
<element name="PreferredStockLineItems" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_PreferredStockLineItems" substitutionGroup="xbrli:item" />
<element name="HmsVictoryProjectMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_HmsVictoryProjectMember" substitutionGroup="xbrli:item" />
<element name="SeattleProjectMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_SeattleProjectMember" substitutionGroup="xbrli:item" />
<element name="GaltResourcesLlcMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_GaltResourcesLlcMember" substitutionGroup="xbrli:item" />
<element name="InvestmentsAxis" type="xbrli:stringItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_InvestmentsAxis" substitutionGroup="xbrldt:dimensionItem" />
<element name="InvestmentsCategorizationDomain" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_InvestmentsCategorizationDomain" substitutionGroup="xbrli:item" />
<element name="RevenueParticipationCertificatesMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_RevenueParticipationCertificatesMember" substitutionGroup="xbrli:item" />
<element name="PercentageOfRevenueOwedToCertificateHolders" type="num:percentItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="omex_PercentageOfRevenueOwedToCertificateHolders" substitutionGroup="xbrli:item" />
<element name="InvestmentMultiplierInCaseOfProjectSuccess" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_InvestmentMultiplierInCaseOfProjectSuccess" substitutionGroup="xbrli:item" />
<element name="InvestmentForFutureRevenueRights" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_InvestmentForFutureRevenueRights" substitutionGroup="xbrli:item" xbrli:balance="debit" />
<element name="RevenueParticipationCertificatesPerUnitValue" type="srt-types:perUnitItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_RevenueParticipationCertificatesPerUnitValue" substitutionGroup="xbrli:item" />
<element name="RevenueParticipationAgreementValue" type="xbrli:monetaryItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="omex_RevenueParticipationAgreementValue" substitutionGroup="xbrli:item" xbrli:balance="credit" />
<element name="NumberOfProjectsAfterBifurcation" type="xbrli:integerItemType" abstract="false" xbrli:periodType="duration" nillable="true" id="omex_NumberOfProjectsAfterBifurcation" substitutionGroup="xbrli:item" />
<element name="CommonSharesIssuedPerUnit" type="xbrli:sharesItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="omex_CommonSharesIssuedPerUnit" substitutionGroup="xbrli:item" />
<element name="PercentageOfRevenueOwedToCertificateHoldersPerUnit" type="num:percentItemType" abstract="false" xbrli:periodType="instant" nillable="true" id="omex_PercentageOfRevenueOwedToCertificateHoldersPerUnit" substitutionGroup="xbrli:item" />
<element name="SsGairsoppaMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_SsGairsoppaMember" substitutionGroup="xbrli:item" />
<element name="GaltResourcesLlcHmsVictoryMember" type="nonnum:domainItemType" abstract="true" xbrli:periodType="duration" nillable="true" id="omex_GaltResourcesLlcHmsVictoryMember" substitutionGroup="xbrli:item" />
</schema>
