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        <BusinessCd>900099</BusinessCd>
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        <RelatedOrExemptFuncIncomeAmt>138794</RelatedOrExemptFuncIncomeAmt>
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      <ProgramServiceRevenueGrp>
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      </ProgramServiceRevenueGrp>
      <TotalProgramServiceRevenueAmt>1202369</TotalProgramServiceRevenueAmt>
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      </IncmFromInvestBondProceedsGrp>
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      </RoyaltiesRevenueGrp>
      <NetRentalIncomeOrLossGrp>
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      </NetRentalIncomeOrLossGrp>
      <GrossAmountSalesAssetsGrp>
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      </GrossAmountSalesAssetsGrp>
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      <NetGainOrLossInvestmentsGrp>
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        <RelatedOrExemptFuncIncomeAmt>796990</RelatedOrExemptFuncIncomeAmt>
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      <FundraisingGrossIncomeAmt>142632</FundraisingGrossIncomeAmt>
      <FundraisingDirectExpensesAmt>53537</FundraisingDirectExpensesAmt>
      <NetIncmFromFundraisingEvtGrp>
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      </NetIncmFromFundraisingEvtGrp>
      <NetIncomeFromGamingGrp>
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      </NetIncomeFromGamingGrp>
      <NetIncomeOrLossGrp>
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      </NetIncomeOrLossGrp>
      <OtherRevenueMiscGrp>
        <Desc>Other Income</Desc>
        <BusinessCd>900099</BusinessCd>
        <TotalRevenueColumnAmt>3525</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>3525</RelatedOrExemptFuncIncomeAmt>
      </OtherRevenueMiscGrp>
      <OtherRevenueTotalAmt>3525</OtherRevenueTotalAmt>
      <TotalRevenueGrp>
        <TotalRevenueColumnAmt>2252266</TotalRevenueColumnAmt>
        <RelatedOrExemptFuncIncomeAmt>2158204</RelatedOrExemptFuncIncomeAmt>
      </TotalRevenueGrp>
      <GrantsToDomesticOrgsGrp>
        <TotalAmt>0</TotalAmt>
      </GrantsToDomesticOrgsGrp>
      <GrantsToDomesticIndividualsGrp>
        <TotalAmt>82787</TotalAmt>
        <ProgramServicesAmt>82787</ProgramServicesAmt>
      </GrantsToDomesticIndividualsGrp>
      <ForeignGrantsGrp>
        <TotalAmt>0</TotalAmt>
      </ForeignGrantsGrp>
      <BenefitsToMembersGrp>
        <TotalAmt>0</TotalAmt>
      </BenefitsToMembersGrp>
      <CompCurrentOfcrDirectorsGrp>
        <TotalAmt>181400</TotalAmt>
        <ProgramServicesAmt>90700</ProgramServicesAmt>
        <ManagementAndGeneralAmt>90700</ManagementAndGeneralAmt>
      </CompCurrentOfcrDirectorsGrp>
      <CompDisqualPersonsGrp>
        <TotalAmt>0</TotalAmt>
      </CompDisqualPersonsGrp>
      <OtherSalariesAndWagesGrp>
        <TotalAmt>387316</TotalAmt>
        <ProgramServicesAmt>252661</ProgramServicesAmt>
        <ManagementAndGeneralAmt>134655</ManagementAndGeneralAmt>
      </OtherSalariesAndWagesGrp>
      <PensionPlanContributionsGrp>
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        <ProgramServicesAmt>15535</ProgramServicesAmt>
        <ManagementAndGeneralAmt>17656</ManagementAndGeneralAmt>
      </PensionPlanContributionsGrp>
      <OtherEmployeeBenefitsGrp>
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        <ProgramServicesAmt>34478</ProgramServicesAmt>
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      </OtherEmployeeBenefitsGrp>
      <PayrollTaxesGrp>
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        <ProgramServicesAmt>27993</ProgramServicesAmt>
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      </PayrollTaxesGrp>
      <FeesForServicesManagementGrp>
        <TotalAmt>0</TotalAmt>
      </FeesForServicesManagementGrp>
      <FeesForServicesLegalGrp>
        <TotalAmt>34488</TotalAmt>
        <ManagementAndGeneralAmt>34488</ManagementAndGeneralAmt>
      </FeesForServicesLegalGrp>
      <FeesForServicesAccountingGrp>
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        <ManagementAndGeneralAmt>102526</ManagementAndGeneralAmt>
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      <FeesForServicesProfFundraising>
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      <FeesForSrvcInvstMgmntFeesGrp>
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      <AdvertisingGrp>
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      </AdvertisingGrp>
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      <InformationTechnologyGrp>
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      <RoyaltiesGrp>
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      <OccupancyGrp>
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        <ManagementAndGeneralAmt>67486</ManagementAndGeneralAmt>
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      <PymtTravelEntrtnmntPubOfclGrp>
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      <InterestGrp>
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      <PaymentsToAffiliatesGrp>
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        <ManagementAndGeneralAmt>24258</ManagementAndGeneralAmt>
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      <InsuranceGrp>
        <TotalAmt>29058</TotalAmt>
        <ManagementAndGeneralAmt>29058</ManagementAndGeneralAmt>
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      <OtherExpensesGrp>
        <Desc>Printing and Publications</Desc>
        <TotalAmt>65571</TotalAmt>
        <ProgramServicesAmt>65571</ProgramServicesAmt>
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      <OtherExpensesGrp>
        <Desc>Other</Desc>
        <TotalAmt>19751</TotalAmt>
        <ProgramServicesAmt>4006</ProgramServicesAmt>
        <ManagementAndGeneralAmt>15745</ManagementAndGeneralAmt>
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      <OtherExpensesGrp>
        <Desc>Subscriptions</Desc>
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        <ManagementAndGeneralAmt>8376</ManagementAndGeneralAmt>
      </OtherExpensesGrp>
      <OtherExpensesGrp>
        <Desc>Membership Dues</Desc>
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        <ProgramServicesAmt>5475</ProgramServicesAmt>
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      <AllOtherExpensesGrp>
        <TotalAmt>4430</TotalAmt>
        <ProgramServicesAmt>3547</ProgramServicesAmt>
        <ManagementAndGeneralAmt>883</ManagementAndGeneralAmt>
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      <TotalFunctionalExpensesGrp>
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        <ProgramServicesAmt>1808545</ProgramServicesAmt>
        <ManagementAndGeneralAmt>698930</ManagementAndGeneralAmt>
        <FundraisingAmt>0</FundraisingAmt>
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      <CashNonInterestBearingGrp>
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      <PledgesAndGrantsReceivableGrp>
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      <AccountsReceivableGrp>
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      <ReceivablesFromOfficersEtcGrp>
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      <InventoriesForSaleOrUseGrp>
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      <InvestmentsOtherSecuritiesGrp>
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      <InvestmentsProgramRelatedGrp>
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      <TotalAssetsGrp>
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      <AccountsPayableAccrExpnssGrp>
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      <MortgNotesPyblScrdInvstPropGrp>
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      <TotalLiabilitiesGrp>
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        <EOYAmt>451772</EOYAmt>
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      <OrganizationFollowsFASB117Ind>X</OrganizationFollowsFASB117Ind>
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        <EOYAmt>6954855</EOYAmt>
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      <TotalNetAssetsFundBalanceGrp>
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        <EOYAmt>6954855</EOYAmt>
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      <TotLiabNetAssetsFundBalanceGrp>
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      <ReconcilationRevenueExpnssAmt>-255209</ReconcilationRevenueExpnssAmt>
      <NetUnrlzdGainsLossesInvstAmt>-789463</NetUnrlzdGainsLossesInvstAmt>
      <PriorPeriodAdjustmentsAmt>715</PriorPeriodAdjustmentsAmt>
      <MethodOfAccountingAccrualInd>X</MethodOfAccountingAccrualInd>
      <AccountantCompileOrReviewInd>false</AccountantCompileOrReviewInd>
      <FSAuditedInd>true</FSAuditedInd>
      <FSAuditedBasisGrp>
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      <AuditCommitteeInd>true</AuditCommitteeInd>
      <FederalGrantAuditRequiredInd>false</FederalGrantAuditRequiredInd>
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        <CurrentTaxYearMinus3YearsAmt>187914</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>212577</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>131952</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>143761</CurrentTaxYearAmt>
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      <GrossReceiptsAdmissionsGrp>
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        <CurrentTaxYearMinus2YearsAmt>2544844</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>2579192</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>1949660</CurrentTaxYearAmt>
        <TotalAmt>12731623</TotalAmt>
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      <GrossReceiptsNonUnrltBusGrp>
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      <TaxRevLeviedOrgnztnlBnft509Grp>
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      <GovtFurnSrvcFcltsVl509Grp>
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        <CurrentTaxYearMinus3YearsAmt>2795382</CurrentTaxYearMinus3YearsAmt>
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        <CurrentTaxYearMinus1YearAmt>2711144</CurrentTaxYearMinus1YearAmt>
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      <OtherIncome509Grp>
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        <CurrentTaxYearMinus3YearsAmt>893</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>46103</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>4712</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>3525</CurrentTaxYearAmt>
        <TotalAmt>55806</TotalAmt>
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      <TotalSupportCalendarYearGrp>
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        <CurrentTaxYearMinus3YearsAmt>2941124</CurrentTaxYearMinus3YearsAmt>
        <CurrentTaxYearMinus2YearsAmt>2983768</CurrentTaxYearMinus2YearsAmt>
        <CurrentTaxYearMinus1YearAmt>2871813</CurrentTaxYearMinus1YearAmt>
        <CurrentTaxYearAmt>2252266</CurrentTaxYearAmt>
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      <InvestmentIncomePYPct>0.05990</InvestmentIncomePYPct>
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        <BookValueAmt>895</BookValueAmt>
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      <RevenueNotReportedAmt>-735926</RevenueNotReportedAmt>
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      <TotalRevenuePerForm990Amt>2252266</TotalRevenuePerForm990Amt>
      <TotExpnsEtcAuditedFinclStmtAmt>2561012</TotExpnsEtcAuditedFinclStmtAmt>
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      <ExpensesNotReportedAmt>53537</ExpensesNotReportedAmt>
      <ExpensesSubtotalAmt>2507475</ExpensesSubtotalAmt>
      <TotalExpensesPerForm990Amt>2507475</TotalExpensesPerForm990Amt>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part XI, Line 2d: Other revenue amounts included in F/S but not included on form 990</FormAndLineReferenceDesc>
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      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part XII, Line 2d: Other expenses and losses per audited F/S</FormAndLineReferenceDesc>
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    </IRS990ScheduleD>
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        <OfficesCnt>0</OfficesCnt>
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        <TypeOfActivitiesConductedTxt>Program Services</TypeOfActivitiesConductedTxt>
        <SpecificServicesProvidedTxt>OCEANS 2020 conferences</SpecificServicesProvidedTxt>
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      </AccountActivitiesOutsideUSGrp>
      <AccountActivitiesOutsideUSGrp>
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        <EmployeeCnt>0</EmployeeCnt>
        <TypeOfActivitiesConductedTxt>Program Services</TypeOfActivitiesConductedTxt>
        <SpecificServicesProvidedTxt>International Buoy Workshop</SpecificServicesProvidedTxt>
        <RegionTotalExpendituresAmt>8468</RegionTotalExpendituresAmt>
      </AccountActivitiesOutsideUSGrp>
      <AccountActivitiesOutsideUSGrp>
        <RegionTxt>South America</RegionTxt>
        <OfficesCnt>0</OfficesCnt>
        <EmployeeCnt>0</EmployeeCnt>
        <TypeOfActivitiesConductedTxt>Program Services</TypeOfActivitiesConductedTxt>
        <SpecificServicesProvidedTxt>OTC</SpecificServicesProvidedTxt>
        <RegionTotalExpendituresAmt>7233</RegionTotalExpendituresAmt>
      </AccountActivitiesOutsideUSGrp>
      <SubtotalEmployeesCnt>4</SubtotalEmployeesCnt>
      <TotalEmployeeCnt>4</TotalEmployeeCnt>
      <SubtotalSpentAmt>19610</SubtotalSpentAmt>
      <TotalSpentAmt>19610</TotalSpentAmt>
      <TransferToForeignCorpInd>false</TransferToForeignCorpInd>
      <InterestInForeignTrustInd>false</InterestInForeignTrustInd>
      <ForeignCorpOwnershipInd>false</ForeignCorpOwnershipInd>
      <PassiveForeignInvestmestCoInd>false</PassiveForeignInvestmestCoInd>
      <ForeignPartnershipInd>false</ForeignPartnershipInd>
      <BoycottCountriesInd>false</BoycottCountriesInd>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part I, Line 3f - Method of Accounting</FormAndLineReferenceDesc>
        <ExplanationTxt>US GAAP: Accrual Basis of Accounting</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Part I, Line 3f - Investments and Expenditures</FormAndLineReferenceDesc>
        <ExplanationTxt>Program Services Expenses consist of Conferences and Workshops Expenses.South America: $7,233East Asia and the Pacific Expenses: $8,468Europe: $3,909</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleF>
    <IRS990ScheduleG documentId="IRS990ScheduleG" softwareId="19009920" softwareVersionNum="2019v5.0">
      <AgrmtProfFundraisingActyInd>false</AgrmtProfFundraisingActyInd>
      <FundraisingEventInformationGrp>
        <Event1Nm>SportClay</Event1Nm>
        <GrossReceiptsEvent1Amt>112670</GrossReceiptsEvent1Amt>
        <GrossRevenueEvent1Amt>112670</GrossRevenueEvent1Amt>
        <RentFacilityCostsEvent1Amt>37538</RentFacilityCostsEvent1Amt>
        <OtherDirectExpensesEvent1Amt>3039</OtherDirectExpensesEvent1Amt>
        <Event2Nm>BBQ</Event2Nm>
        <GrossReceiptsEvent2Amt>29962</GrossReceiptsEvent2Amt>
        <GrossRevenueEvent2Amt>29962</GrossRevenueEvent2Amt>
        <RentFacilityCostsEvent2Amt>4296</RentFacilityCostsEvent2Amt>
        <FoodAndBeverageEvent2Amt>7770</FoodAndBeverageEvent2Amt>
        <OtherDirectExpensesEvent2Amt>894</OtherDirectExpensesEvent2Amt>
        <GrossReceiptsTotalAmt>142632</GrossReceiptsTotalAmt>
        <GrossRevenueTotalEventsAmt>142632</GrossRevenueTotalEventsAmt>
        <RentFcltyCostsTotalEventsAmt>41834</RentFcltyCostsTotalEventsAmt>
        <FoodAndBeverageTotalEventsAmt>7770</FoodAndBeverageTotalEventsAmt>
        <OthDirectExpnssTotalEventsAmt>3933</OthDirectExpnssTotalEventsAmt>
        <DirectExpenseSummaryEventsAmt>53537</DirectExpenseSummaryEventsAmt>
        <NetIncomeSummaryAmt>89095</NetIncomeSummaryAmt>
      </FundraisingEventInformationGrp>
    </IRS990ScheduleG>
    <IRS990ScheduleI documentId="IRS990ScheduleI" softwareId="19009920" softwareVersionNum="2019v5.0">
      <GrantRecordsMaintainedInd>true</GrantRecordsMaintainedInd>
      <Total501c3OrgCnt>0</Total501c3OrgCnt>
      <TotalOtherOrgCnt>0</TotalOtherOrgCnt>
      <GrantsOtherAsstToIndivInUSGrp>
        <GrantTypeTxt>Tuition Scholarships</GrantTypeTxt>
        <RecipientCnt>15</RecipientCnt>
        <CashGrantAmt>82787</CashGrantAmt>
      </GrantsOtherAsstToIndivInUSGrp>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Grantmaker's Description of How Grants are Used</FormAndLineReferenceDesc>
        <ExplanationTxt>An open solicitation for scholarship applications is held and applications are first reviewed by staff to ensure proper format and completeness. The prepared scholarship package is then sent to a committee for grading and selection of the recipients. Funds are disbursed directly to the bursar of the colleges attended but given to the scholarship winners.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleI>
    <IRS990ScheduleJ documentId="IRS990ScheduleJ" softwareId="19009920" softwareVersionNum="2019v5.0">
      <CompensationCommitteeInd>X</CompensationCommitteeInd>
      <WrittenEmploymentContractInd>X</WrittenEmploymentContractInd>
      <BoardOrCommitteeApprovalInd>X</BoardOrCommitteeApprovalInd>
      <SeverancePaymentInd>false</SeverancePaymentInd>
      <SupplementalNonqualRtrPlanInd>false</SupplementalNonqualRtrPlanInd>
      <EquityBasedCompArrngmInd>false</EquityBasedCompArrngmInd>
      <CompBasedOnRevenueOfFlngOrgInd>false</CompBasedOnRevenueOfFlngOrgInd>
      <CompBsdOnRevRelatedOrgsInd>false</CompBsdOnRevRelatedOrgsInd>
      <CompBsdNetEarnsFlngOrgInd>false</CompBsdNetEarnsFlngOrgInd>
      <CompBsdNetEarnsRltdOrgsInd>false</CompBsdNetEarnsRltdOrgsInd>
      <AnyNonFixedPaymentsInd>false</AnyNonFixedPaymentsInd>
      <InitialContractExceptionInd>false</InitialContractExceptionInd>
      <RltdOrgOfficerTrstKeyEmplGrp>
        <PersonNm>Kathleen Herndon</PersonNm>
        <TitleTxt>Executive Dir.</TitleTxt>
        <BaseCompensationFilingOrgAmt>153846</BaseCompensationFilingOrgAmt>
        <BonusFilingOrganizationAmount>19000</BonusFilingOrganizationAmount>
        <DeferredCompensationFlngOrgAmt>5486</DeferredCompensationFlngOrgAmt>
        <NontaxableBenefitsFilingOrgAmt>2099</NontaxableBenefitsFilingOrgAmt>
        <TotalCompensationFilingOrgAmt>180431</TotalCompensationFilingOrgAmt>
      </RltdOrgOfficerTrstKeyEmplGrp>
    </IRS990ScheduleJ>
    <IRS990ScheduleO documentId="IRS990ScheduleO" softwareId="19009920" softwareVersionNum="2019v5.0">
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990, Part III, Line 4d: Other Program Services Description</FormAndLineReferenceDesc>
        <ExplanationTxt>OTHER PROGRAM SERVICES 4: Educational programs: other educational programs supporting society's mission.Professional Development: in January 2020, MTS entered into a pilot program in cooperation with the Society for Underwater Technology (SUT) to offer the Chartered Marine Technologist (CMarTech) credential. The pilot program evaluated eight (8) candidates and was completed in November 2020. OTHER PROGRAM SERVICES 5: Communications: provides news and information to members and the broader marine science and technology community on a variety of channels including newsletters, MTS's website, and social media.U.N. Decade of Ocean Science for Sustainable Development: MTS participated in the Global Planning meeting for the Decade and joined the effort as a U.S. Committee Nexus Partner. MTS will offer representatives to Decade events, articles in the Journal about Decade topics, and webinars focused on Decade topics.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990, Part VI, Line 6: Explanation of Classes of Members or Shareholder</FormAndLineReferenceDesc>
        <ExplanationTxt>The classes of society's membership are as follows: member, associate member, student member, patron, emeritus member,complimentary member, life member, honorary member, business member, and institutional member.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990, Part VI, Line 11b: Form 990 Review Process</FormAndLineReferenceDesc>
        <ExplanationTxt>Form 990 is prepared by an independent accounting firm and reviewed by the society's executive director and treasurer/VP of budget and finance. The draft form 990 is then provided to the full board of directors prior to the filing with the Internal revenue service.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990, Part VI, Line 12c: Explanation of Monitoring and Enforcement of Conflicts</FormAndLineReferenceDesc>
        <ExplanationTxt>The Society requires completion of annual disclosure form of any potential conflicts of interest by all officers, directors, and committee chairs.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990, Part VI, Line 15a: Compensation Review &amp; Approval Process - CEO, Top Management</FormAndLineReferenceDesc>
        <ExplanationTxt>The Society's Board of directors approves the compensation of the executive director and documents the arrangement through an employment contract.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>Form 990, Part VI, Line 19: Other Organization Documents Publicly Available</FormAndLineReferenceDesc>
        <ExplanationTxt>The Organization makes its form 1023 available to the public upon request. Form 990 is also available to the public on the guidestar website and on the organization's own website.The Organization makes its governing documents and conflicts of interest policy available to the public on its website. The financial statements are available to the public upon request.</ExplanationTxt>
      </SupplementalInformationDetail>
      <SupplementalInformationDetail>
        <FormAndLineReferenceDesc>M 990, PART V, LINE 1C - BACKUP WITHHOLDING RULES</FormAndLineReferenceDesc>
        <ExplanationTxt>BACKUP WITHHOLDING RULES DID NOT APPLY TO THE ORGANIZATION BUT IF THEY WOULD APPLY THE ORGANIZATION WOULD COMPLY.</ExplanationTxt>
      </SupplementalInformationDetail>
    </IRS990ScheduleO>
  </ReturnData>
</Return>