<?xml version="1.0" encoding="us-ascii"?>
<!--XBRL document created with Toppan Merrill Bridge  9.6.8119.21675 -->
<!--Based on XBRL 2.1-->
<!--Created on: 4/27/2022 8:07:44 PM-->
<!--Modified on: 4/27/2022 8:07:44 PM-->
<xsd:schema xmlns:xbrldt="http://xbrl.org/2005/xbrldt" xmlns:xlink="http://www.w3.org/1999/xlink" xmlns:link="http://www.xbrl.org/2003/linkbase" xmlns:xbrli="http://www.xbrl.org/2003/instance" targetNamespace="http://www.helixesg.com/20220331" attributeFormDefault="unqualified" elementFormDefault="qualified" xmlns:xsd="http://www.w3.org/2001/XMLSchema" xmlns:hlx="http://www.helixesg.com/20220331" xmlns:enum2="http://xbrl.org/2020/extensible-enumerations-2.0" xmlns:srt-types="http://fasb.org/srt-types/2021-01-31" xmlns:dtr-types="http://www.xbrl.org/dtr/type/2020-01-21" xmlns:currency="http://xbrl.sec.gov/currency/2021" xmlns:us-roles="http://fasb.org/us-roles/2021-01-31" xmlns:ref="http://www.xbrl.org/2006/ref" xmlns:xl="http://www.xbrl.org/2003/XLink" xmlns:sic="http://xbrl.sec.gov/sic/2021" xmlns:us-types="http://fasb.org/us-types/2021-01-31" xmlns:srt-roles="http://fasb.org/srt-roles/2021-01-31" xmlns:stpr="http://xbrl.sec.gov/stpr/2021" xmlns:utr="http://www.xbrl.org/2009/utr" xmlns:us-gaap="http://fasb.org/us-gaap/2021-01-31" xmlns:exch="http://xbrl.sec.gov/exch/2021" xmlns:naics="http://xbrl.sec.gov/naics/2021" xmlns:country="http://xbrl.sec.gov/country/2021" xmlns:negated="http://www.xbrl.org/2009/role/negated" xmlns:attributeFormDefault="unqualified" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xmlns:srt="http://fasb.org/srt/2021-01-31" xmlns:deprecated="http://www.xbrl.org/2009/role/deprecated" xmlns:net="http://www.xbrl.org/2009/role/net" xmlns:dei="http://xbrl.sec.gov/dei/2021q4">
  <xsd:annotation>
    <xsd:appinfo>
      <link:roleType roleURI="http://www.helixesg.com/role/DisclosureStandardAndCustomAxisDomainDefaults" id="DisclosureStandardAndCustomAxisDomainDefaults">
        <link:definition>99900 - Disclosure - Standard And Custom Axis Domain Defaults</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://www.helixesg.com/role/StatementCondensedConsolidatedBalanceSheets" id="StatementCondensedConsolidatedBalanceSheets">
        <link:definition>00100 - Statement - Condensed Consolidated Balance Sheets</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://www.helixesg.com/role/StatementCondensedConsolidatedStatementsOfOperations" id="StatementCondensedConsolidatedStatementsOfOperations">
        <link:definition>00200 - Statement - Condensed Consolidated Statements Of Operations</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://www.helixesg.com/role/StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss" id="StatementCondensedConsolidatedStatementsOfComprehensiveIncomeLoss">
        <link:definition>00300 - Statement - Condensed Consolidated Statements Of Comprehensive Income (Loss)</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://www.helixesg.com/role/StatementCondensedConsolidatedStatementsOfCashFlows" id="StatementCondensedConsolidatedStatementsOfCashFlows">
        <link:definition>00500 - Statement - Condensed Consolidated Statements Of Cash Flows</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://www.helixesg.com/role/DisclosureDetailsOfCertainAccountsOtherCurrentAssetsDetails" id="DisclosureDetailsOfCertainAccountsOtherCurrentAssetsDetails">
        <link:definition>40301 - Disclosure - Details Of Certain Accounts - Other Current Assets (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://www.helixesg.com/role/DisclosureDetailsOfCertainAccountsOtherAssetsNetDetails" id="DisclosureDetailsOfCertainAccountsOtherAssetsNetDetails">
        <link:definition>40302 - Disclosure - Details Of Certain Accounts - Other 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://www.helixesg.com/role/DisclosureDetailsOfCertainAccountsAccruedLiabilitiesDetails" id="DisclosureDetailsOfCertainAccountsAccruedLiabilitiesDetails">
        <link:definition>40303 - Disclosure - Details Of Certain Accounts - Accrued 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://www.helixesg.com/role/DisclosureDetailsOfCertainAccountsOtherNonCurrentLiabilitiesDetails" id="DisclosureDetailsOfCertainAccountsOtherNonCurrentLiabilitiesDetails">
        <link:definition>40304 - Disclosure - Details Of Certain Accounts - Other Non-Current 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://www.helixesg.com/role/DisclosureLeasesComponentsOfLeaseCostDetails" id="DisclosureLeasesComponentsOfLeaseCostDetails">
        <link:definition>40401 - Disclosure - Leases - Components Of 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://www.helixesg.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails" id="DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesDetails">
        <link:definition>40402 - Disclosure - Leases - Maturities Of Operating Lease 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://www.helixesg.com/role/DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesCalc2" id="DisclosureLeasesMaturitiesOfOperatingLeaseLiabilitiesCalc2">
        <link:definition>40403 - Disclosure - Leases - Maturities Of Operating Lease Liabilities (Calc 2)</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://www.helixesg.com/role/DisclosureLongTermDebtMaturitiesOfLongTermDebtDetails" id="DisclosureLongTermDebtMaturitiesOfLongTermDebtDetails">
        <link:definition>40501 - Disclosure - Long-Term Debt - Maturities Of 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://www.helixesg.com/role/DisclosureLongTermDebtMaturitiesOfLongTermDebtCalc2" id="DisclosureLongTermDebtMaturitiesOfLongTermDebtCalc2">
        <link:definition>40509 - Disclosure - Long-Term Debt - Maturities Of Long-Term Debt (Calc 2)</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://www.helixesg.com/role/DisclosureLongTermDebtComponentsOfNetInterestExpenseDetails" id="DisclosureLongTermDebtComponentsOfNetInterestExpenseDetails">
        <link:definition>40510 - Disclosure - Long-Term Debt - Components Of Net Interest Expense (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://www.helixesg.com/role/DisclosureEarningsPerShareComputationsOfBasicAndDilutedEpsDetails" id="DisclosureEarningsPerShareComputationsOfBasicAndDilutedEpsDetails">
        <link:definition>40801 - Disclosure - Earnings Per Share - Computations Of Basic And Diluted EPS (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://www.helixesg.com/role/DisclosureEarningsPerShareSharesIncludedInDilutedCalculationsAssumingEarningsDetails" id="DisclosureEarningsPerShareSharesIncludedInDilutedCalculationsAssumingEarningsDetails">
        <link:definition>40802 - Disclosure - Earnings Per Share - Shares Included in Diluted Calculations Assuming Earnings (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://www.helixesg.com/role/StatementCondensedConsolidatedStatementsOfShareholdersEquity" id="StatementCondensedConsolidatedStatementsOfShareholdersEquity">
        <link:definition>00400 - Statement - Condensed Consolidated Statements Of Shareholders' Equity</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://www.helixesg.com/role/DisclosureCompanyOverviewDetails" id="DisclosureCompanyOverviewDetails">
        <link:definition>40201 - Disclosure - Company Overview (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://www.helixesg.com/role/DisclosureLongTermDebtCreditAgreementDetails" id="DisclosureLongTermDebtCreditAgreementDetails">
        <link:definition>40502 - Disclosure - Long-Term Debt - Credit Agreement (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://www.helixesg.com/role/DisclosureLongTermDebtConvertibleSeniorNotesDue2022Details" id="DisclosureLongTermDebtConvertibleSeniorNotesDue2022Details">
        <link:definition>40503 - Disclosure - Long-Term Debt - Convertible Senior Notes Due 2022 (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://www.helixesg.com/role/DisclosureLongTermDebtConvertibleSeniorNotesDue2023Details" id="DisclosureLongTermDebtConvertibleSeniorNotesDue2023Details">
        <link:definition>40504 - Disclosure - Long-Term Debt - Convertible Senior Notes Due 2023 (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://www.helixesg.com/role/DisclosureLongTermDebtConvertibleSeniorNotesDue2026Details" id="DisclosureLongTermDebtConvertibleSeniorNotesDue2026Details">
        <link:definition>40505 - Disclosure - Long-Term Debt - Convertible Senior Notes Due 2026 (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://www.helixesg.com/role/DisclosureLongTermDebt2026CappedCallsDetails" id="DisclosureLongTermDebt2026CappedCallsDetails">
        <link:definition>40506 - Disclosure - Long-Term Debt - 2026 Capped Calls (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://www.helixesg.com/role/DisclosureLongTermDebtMaradDebtDetails" id="DisclosureLongTermDebtMaradDebtDetails">
        <link:definition>40507 - Disclosure - Long-Term Debt - MARAD 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://www.helixesg.com/role/DisclosureLongTermDebtFormerNordeaQ5000LoanDetails" id="DisclosureLongTermDebtFormerNordeaQ5000LoanDetails">
        <link:definition>40508 - Disclosure - Long-Term Debt - Former Nordea Q5000 Loan (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://www.helixesg.com/role/DisclosureLongTermDebtFormerCreditAgreementDetails" id="DisclosureLongTermDebtFormerCreditAgreementDetails">
        <link:definition>40509 - Disclosure - Long-Term Debt - Former Credit Agreement (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://www.helixesg.com/role/DisclosureRevenueFromContractsWithCustomersDisaggregationOfRevenueDetails" id="DisclosureRevenueFromContractsWithCustomersDisaggregationOfRevenueDetails">
        <link:definition>40701 - Disclosure - Revenue From Contracts With Customers - Disaggregation Of Revenue (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://www.helixesg.com/role/DisclosureRevenueFromContractsWithCustomersRemainingPerformanceObligationsDetails" id="DisclosureRevenueFromContractsWithCustomersRemainingPerformanceObligationsDetails">
        <link:definition>40703 - Disclosure - Revenue From Contracts With Customers - Remaining Performance Obligations (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://www.helixesg.com/role/DisclosureRevenueFromContractsWithCustomersRemainingPerformanceObligationsDefaultDetails" id="DisclosureRevenueFromContractsWithCustomersRemainingPerformanceObligationsDefaultDetails">
        <link:definition>40703 - Disclosure - Revenue From Contracts With Customers - Remaining Performance Obligations Default (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://www.helixesg.com/role/DisclosureEarningsPerSharePotentiallyDilutiveSharesExcludedFromDilutedEpsCalculationDetails" id="DisclosureEarningsPerSharePotentiallyDilutiveSharesExcludedFromDilutedEpsCalculationDetails">
        <link:definition>40803 - Disclosure - Earnings Per Share - Potentially Dilutive Shares Excluded From Diluted EPS Calculation (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://www.helixesg.com/role/DisclosureEmployeeBenefitPlansNarrativeDetails" id="DisclosureEmployeeBenefitPlansNarrativeDetails">
        <link:definition>40901 - Disclosure - Employee Benefit Plans - Narrative (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://www.helixesg.com/role/DisclosureEmployeeBenefitPlansShareBasedAwardsGrantedDetails" id="DisclosureEmployeeBenefitPlansShareBasedAwardsGrantedDetails">
        <link:definition>40902 - Disclosure - Employee Benefit Plans - Share-Based Awards Granted (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://www.helixesg.com/role/DisclosureBusinessSegmentInformationNarrativeDetails" id="DisclosureBusinessSegmentInformationNarrativeDetails">
        <link:definition>41001 - Disclosure - Business Segment Information - Narrative (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://www.helixesg.com/role/DisclosureBusinessSegmentInformationFinancialDataByReportableSegmentDetails" id="DisclosureBusinessSegmentInformationFinancialDataByReportableSegmentDetails">
        <link:definition>41002 - Disclosure - Business Segment Information - Financial Data By Reportable Segment (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://www.helixesg.com/role/DisclosureBusinessSegmentInformationIntercompanySegmentRevenuesDetails" id="DisclosureBusinessSegmentInformationIntercompanySegmentRevenuesDetails">
        <link:definition>41003 - Disclosure - Business Segment Information - Intercompany Segment 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://www.helixesg.com/role/DisclosureBusinessSegmentInformationTotalAssetsByReportableSegmentDetails" id="DisclosureBusinessSegmentInformationTotalAssetsByReportableSegmentDetails">
        <link:definition>41004 - Disclosure - Business Segment Information - Total Assets By Reportable Segment (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://www.helixesg.com/role/DisclosureStatementOfCashFlowInformationSupplementalCashFlowInformationDetails" id="DisclosureStatementOfCashFlowInformationSupplementalCashFlowInformationDetails">
        <link:definition>41301 - Disclosure - Statement Of Cash Flow Information - Supplemental Cash Flow 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://www.helixesg.com/role/DisclosureAllowanceForCreditLossesActivitiesInAllowanceForCreditLossesDetails" id="DisclosureAllowanceForCreditLossesActivitiesInAllowanceForCreditLossesDetails">
        <link:definition>41401 - Disclosure - Allowance For Credit Losses - Activities In Allowance For Credit 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://www.helixesg.com/role/DisclosureFairValueMeasurementsPrincipalAmountAndEstimatedFairValueOfLongTermDebtDetails" id="DisclosureFairValueMeasurementsPrincipalAmountAndEstimatedFairValueOfLongTermDebtDetails">
        <link:definition>41501 - Disclosure - Fair Value Measurements - Principal Amount And Estimated Fair Value Of 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://www.helixesg.com/role/DocumentDocumentAndEntityInformation" id="DocumentDocumentAndEntityInformation">
        <link:definition>00090 - Document - Document And Entity Information</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://www.helixesg.com/role/StatementCondensedConsolidatedBalanceSheetsParenthetical" id="StatementCondensedConsolidatedBalanceSheetsParenthetical">
        <link:definition>00105 - Statement - Condensed Consolidated Balance Sheets (Parenthetical)</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://www.helixesg.com/role/DisclosureBasisOfPresentationAndNewAccountingStandards" id="DisclosureBasisOfPresentationAndNewAccountingStandards">
        <link:definition>10101 - Disclosure - Basis Of Presentation And New Accounting Standards</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://www.helixesg.com/role/DisclosureCompanyOverview" id="DisclosureCompanyOverview">
        <link:definition>10201 - Disclosure - Company Overview</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://www.helixesg.com/role/DisclosureDetailsOfCertainAccounts" id="DisclosureDetailsOfCertainAccounts">
        <link:definition>10301 - Disclosure - Details Of Certain Accounts</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://www.helixesg.com/role/DisclosureLeases" id="DisclosureLeases">
        <link:definition>10401 - Disclosure - Leases</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://www.helixesg.com/role/DisclosureLongTermDebt" id="DisclosureLongTermDebt">
        <link:definition>10501 - Disclosure - Long-Term Debt</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://www.helixesg.com/role/DisclosureIncomeTaxes" id="DisclosureIncomeTaxes">
        <link:definition>10601 - Disclosure - Income Taxes</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://www.helixesg.com/role/DisclosureRevenueFromContractsWithCustomers" id="DisclosureRevenueFromContractsWithCustomers">
        <link:definition>10701 - Disclosure - Revenue From Contracts With Customers</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://www.helixesg.com/role/DisclosureEarningsPerShare" id="DisclosureEarningsPerShare">
        <link:definition>10801 - Disclosure - Earnings Per Share</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://www.helixesg.com/role/DisclosureEmployeeBenefitPlans" id="DisclosureEmployeeBenefitPlans">
        <link:definition>10901 - Disclosure - Employee Benefit Plans</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://www.helixesg.com/role/DisclosureBusinessSegmentInformation" id="DisclosureBusinessSegmentInformation">
        <link:definition>11001 - Disclosure - Business Segment Information</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://www.helixesg.com/role/DisclosureAssetRetirementObligations" id="DisclosureAssetRetirementObligations">
        <link:definition>11101 - Disclosure - Asset Retirement Obligations</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://www.helixesg.com/role/DisclosureCommitmentsAndContingenciesAndOtherMatters" id="DisclosureCommitmentsAndContingenciesAndOtherMatters">
        <link:definition>11201 - Disclosure - Commitments And Contingencies And Other Matters</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://www.helixesg.com/role/DisclosureStatementOfCashFlowInformation" id="DisclosureStatementOfCashFlowInformation">
        <link:definition>11301 - Disclosure - Statement Of Cash Flow Information</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://www.helixesg.com/role/DisclosureAllowanceForCreditLosses" id="DisclosureAllowanceForCreditLosses">
        <link:definition>11401 - Disclosure - Allowance for Credit Losses</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://www.helixesg.com/role/DisclosureFairValueMeasurements" id="DisclosureFairValueMeasurements">
        <link:definition>11501 - Disclosure - Fair Value Measurements</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://www.helixesg.com/role/DisclosureBasisOfPresentationAndNewAccountingStandardsPolicies" id="DisclosureBasisOfPresentationAndNewAccountingStandardsPolicies">
        <link:definition>20102 - Disclosure - Basis Of Presentation And New Accounting Standards (Policies)</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://www.helixesg.com/role/DisclosureDetailsOfCertainAccountsTables" id="DisclosureDetailsOfCertainAccountsTables">
        <link:definition>30303 - Disclosure - Details Of Certain Accounts (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://www.helixesg.com/role/DisclosureLeasesTables" id="DisclosureLeasesTables">
        <link:definition>30403 - Disclosure - Leases (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://www.helixesg.com/role/DisclosureLongTermDebtTables" id="DisclosureLongTermDebtTables">
        <link:definition>30503 - Disclosure - Long-Term Debt (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://www.helixesg.com/role/DisclosureRevenueFromContractsWithCustomersTables" id="DisclosureRevenueFromContractsWithCustomersTables">
        <link:definition>30703 - Disclosure - Revenue From Contracts With Customers (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://www.helixesg.com/role/DisclosureEarningsPerShareTables" id="DisclosureEarningsPerShareTables">
        <link:definition>30803 - Disclosure - Earnings Per Share (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://www.helixesg.com/role/DisclosureEmployeeBenefitPlansTables" id="DisclosureEmployeeBenefitPlansTables">
        <link:definition>30903 - Disclosure - Employee Benefit Plans (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://www.helixesg.com/role/DisclosureBusinessSegmentInformationTables" id="DisclosureBusinessSegmentInformationTables">
        <link:definition>31003 - Disclosure - Business 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://www.helixesg.com/role/DisclosureAssetRetirementObligationsTables" id="DisclosureAssetRetirementObligationsTables">
        <link:definition>31103 - Disclosure - Asset Retirement Obligations (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://www.helixesg.com/role/DisclosureStatementOfCashFlowInformationTables" id="DisclosureStatementOfCashFlowInformationTables">
        <link:definition>31303 - Disclosure - Statement Of Cash Flow 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://www.helixesg.com/role/DisclosureAllowanceForCreditLossesTables" id="DisclosureAllowanceForCreditLossesTables">
        <link:definition>31403 - Disclosure - Allowance For Credit Losses (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://www.helixesg.com/role/DisclosureFairValueMeasurementsTables" id="DisclosureFairValueMeasurementsTables">
        <link:definition>31503 - Disclosure - Fair Value Measurements (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://www.helixesg.com/role/DisclosureLeasesWeightedAverageRemainingLeaseTermAndDiscountRateDetails" id="DisclosureLeasesWeightedAverageRemainingLeaseTermAndDiscountRateDetails">
        <link:definition>40403 - Disclosure - Leases - Weighted Average Remaining Lease Term And Discount Rate (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://www.helixesg.com/role/DisclosureLeasesOtherInformationRelatedToOperatingLeasesDetails" id="DisclosureLeasesOtherInformationRelatedToOperatingLeasesDetails">
        <link:definition>40404 - Disclosure - Leases - Other Information Related To Operating Leases (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://www.helixesg.com/role/DisclosureIncomeTaxesNarrativeDetails" id="DisclosureIncomeTaxesNarrativeDetails">
        <link:definition>40601 - Disclosure - Income Taxes - Narrative (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://www.helixesg.com/role/DisclosureRevenueFromContractsWithCustomersContractBalancesDetails" id="DisclosureRevenueFromContractsWithCustomersContractBalancesDetails">
        <link:definition>40702 - Disclosure - Revenue From Contracts With Customers - Contract Balances (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://www.helixesg.com/role/DisclosureAssetRetirementObligationsAssetRetirementObligationsDetails" id="DisclosureAssetRetirementObligationsAssetRetirementObligationsDetails">
        <link:definition>41101 - Disclosure - Asset Retirement Obligations - Asset Retirement Obligations (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://www.helixesg.com/role/DisclosureStatementOfCashFlowInformationNarrativeDetails" id="DisclosureStatementOfCashFlowInformationNarrativeDetails">
        <link:definition>41302 - Disclosure - Statement Of Cash Flow Information - Narrative (Details)</link:definition>
        <link:usedOn>link:presentationLink</link:usedOn>
        <link:usedOn>link:calculationLink</link:usedOn>
        <link:usedOn>link:definitionLink</link:usedOn>
      </link:roleType>
      <link:linkbaseRef xlink:type="simple" xlink:href="hlx-20220331_pre.xml" xlink:role="http://www.xbrl.org/2003/role/presentationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="hlx-20220331_cal.xml" xlink:role="http://www.xbrl.org/2003/role/calculationLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="hlx-20220331_def.xml" xlink:role="http://www.xbrl.org/2003/role/definitionLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
      <link:linkbaseRef xlink:type="simple" xlink:href="hlx-20220331_lab.xml" xlink:role="http://www.xbrl.org/2003/role/labelLinkbaseRef" xlink:arcrole="http://www.w3.org/1999/xlink/properties/linkbase" />
    </xsd:appinfo>
  </xsd:annotation>
  <xsd:import namespace="http://xbrl.sec.gov/dei/2021q4" schemaLocation="https://xbrl.sec.gov/dei/2021q4/dei-2021q4.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2003/instance" schemaLocation="http://www.xbrl.org/2003/xbrl-instance-2003-12-31.xsd" />
  <xsd:import namespace="http://www.xbrl.org/dtr/type/2020-01-21" schemaLocation="https://www.xbrl.org/dtr/type/2020-01-21/types.xsd" />
  <xsd:import namespace="http://xbrl.org/2005/xbrldt" schemaLocation="http://www.xbrl.org/2005/xbrldt-2005.xsd" />
  <xsd:import namespace="http://www.xbrl.org/2009/role/negated" schemaLocation="http://www.xbrl.org/lrr/role/negated-2009-12-16.xsd" />
  <xsd:import namespace="http://fasb.org/us-roles/2021-01-31" schemaLocation="https://xbrl.fasb.org/us-gaap/2021/elts/us-roles-2021-01-31.xsd" />
  <xsd:import namespace="http://fasb.org/srt/2021-01-31" schemaLocation="https://xbrl.fasb.org/srt/2021/elts/srt-2021-01-31.xsd" />
  <xsd:import namespace="http://fasb.org/us-gaap/2021-01-31" schemaLocation="https://xbrl.fasb.org/us-gaap/2021/elts/us-gaap-2021-01-31.xsd" />
  <xsd:import namespace="http://xbrl.sec.gov/country/2021" schemaLocation="https://xbrl.sec.gov/country/2021/country-2021.xsd" />
  <xsd:element name="RoboticsMember" id="hlx_RoboticsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="VesselsMember" id="hlx_VesselsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="TermLoanMaturingDecember2021Member" id="hlx_TermLoanMaturingDecember2021Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FacilitiesAndEquipmentMember" id="hlx_FacilitiesAndEquipmentMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ConvertibleSeniorNotesMaturingFebruary2026Member" id="hlx_ConvertibleSeniorNotesMaturingFebruary2026Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="DocumentAndEntityInformationAbstract" id="hlx_DocumentAndEntityInformationAbstract" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ConvertibleSeniorNotesMaturingSeptember2023Member" id="hlx_ConvertibleSeniorNotesMaturingSeptember2023Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="IncentivePlan2005Member" id="hlx_IncentivePlan2005Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="RoyaltyIncomeAndOther" id="hlx_RoyaltyIncomeAndOther" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="credit" xbrli:periodType="duration" />
  <xsd:element name="MARADDebtMaturingFebruary2027Member" id="hlx_MARADDebtMaturingFebruary2027Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardGrantDate" id="hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardGrantDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfIntercompanySegmentRevenuesTableTextBlock" id="hlx_ScheduleOfIntercompanySegmentRevenuesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="NordeaQ5000LoanMaturingJanuary2021Member" id="hlx_NordeaQ5000LoanMaturingJanuary2021Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ConvertibleSeniorNotesMaturingMay2022Member" id="hlx_ConvertibleSeniorNotesMaturingMay2022Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="RevolvingCreditFacilityMaturingDecember2021Member" id="hlx_RevolvingCreditFacilityMaturingDecember2021Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingDate" id="hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardVestingDate" type="xbrli:dateItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ScheduleOfGrantsOfShareBasedAwardsTableTextBlock" id="hlx_ScheduleOfGrantsOfShareBasedAwardsTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="DeferredRecertificationAndDryDockCostsNet" id="hlx_DeferredRecertificationAndDryDockCostsNet" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:balance="debit" xbrli:periodType="instant" />
  <xsd:element name="WellInterventionMember" id="hlx_WellInterventionMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="WeightedAverageRemainingLeaseTermAndDiscountRateTableTextBlock" id="hlx_WeightedAverageRemainingLeaseTermAndDiscountRateTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="ProductionFacilitiesMember" id="hlx_ProductionFacilitiesMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="OtherInformationRelatedToLesseeOperatingLeasesTableTextBlock" id="hlx_OtherInformationRelatedToLesseeOperatingLeasesTableTextBlock" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="FixedValueCashAwardsMember" id="hlx_FixedValueCashAwardsMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" nillable="true" xbrli:periodType="duration" />
  <xsd:element name="NumberOfLongTermCharteredVessels" id="hlx_NumberOfLongTermCharteredVessels" type="xbrli:integerItemType" substitutionGroup="xbrli:item" abstract="false" nillable="true" xbrli:periodType="instant" />
  <xsd:element id="hlx_CapCallCapPrice" name="CapCallCapPrice" nillable="true" type="dtr-types:perShareItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="hlx_DebtInstrumentConvertibleNumberOfShares" name="DebtInstrumentConvertibleNumberOfShares" nillable="true" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentageBasedOnServiceAndMarketConditions" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentageBasedOnServiceAndMarketConditions" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentageBasedOnServiceAndPerformanceConditions" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAwardVestingRightsPercentageBasedOnServiceAndPerformanceConditions" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="hlx_DebtInstrumentConvertibleIncreaseInConversionRatioForCorporateActivity" name="DebtInstrumentConvertibleIncreaseInConversionRatioForCorporateActivity" nillable="true" type="xbrli:pureItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="hlx_WeightedAverageNumberOfSharesOutstandingIncludingIncrementalSharesDiluted" name="WeightedAverageNumberOfSharesOutstandingIncludingIncrementalSharesDiluted" nillable="true" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="hlx_ShareBasedCompensationArrangementByShareBasedPaymentAwardComponentsOfEquityAwardsGranted" name="ShareBasedCompensationArrangementByShareBasedPaymentAwardComponentsOfEquityAwardsGranted" nillable="true" type="xbrli:integerItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" />
  <xsd:element id="hlx_CouponInterestExpense" name="CouponInterestExpense" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element name="AssetBasedCreditAgreementMaturingSeptember2026Member" id="hlx_AssetBasedCreditAgreementMaturingSeptember2026Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LineOfCreditFacilitySpringingMaturityPeriod" id="hlx_LineOfCreditFacilitySpringingMaturityPeriod" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="LineOfCreditFacilitySpringingMaturityPrincipalAmountThreshold" id="hlx_LineOfCreditFacilitySpringingMaturityPrincipalAmountThreshold" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LineOfCreditFacilityLettersOfCreditSublimit" id="hlx_LineOfCreditFacilityLettersOfCreditSublimit" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="FixedChargeCoverageRatio" id="hlx_FixedChargeCoverageRatio" type="xbrli:pureItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="SterlingOvernightInterbankAverageRateSoniaMember" id="hlx_SterlingOvernightInterbankAverageRateSoniaMember" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
  <xsd:element name="LineOfCreditFacilityRemainingBorrowingCapacityPercentage" id="hlx_LineOfCreditFacilityRemainingBorrowingCapacityPercentage" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
  <xsd:element name="AggregateCostDebtInstrumentConvertibleAssociatedCappedCallTransactionsCost" id="hlx_AggregateCostDebtInstrumentConvertibleAssociatedCappedCallTransactionsCost" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" xbrli:balance="debit" />
  <xsd:element name="MaximumCommitmentIncrease" id="hlx_MaximumCommitmentIncrease" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LineOfCreditFacilityThresholdForBorrowingBaseFixedCoverageRatio" id="hlx_LineOfCreditFacilityThresholdForBorrowingBaseFixedCoverageRatio" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" xbrli:balance="credit" />
  <xsd:element name="LineOfCreditFacilityPeriodPriorToMaturityToMaintainExcessAvailability" id="hlx_LineOfCreditFacilityPeriodPriorToMaturityToMaintainExcessAvailability" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="instant" abstract="false" />
</xsd:schema>
