EX-21.1 4 hlx-20241231xex21d1.htm EX-21.1

EXHIBIT 21.1

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Name of Subsidiary | Jurisdiction of Formation
AES-EOT Equipment Holdings, LLC | Louisiana
Alliance Energy Services, LLC | Louisiana
Alliance Group of Louisiana L.L.C. | Louisiana
Alliance Industry Holdings, LLC | Louisiana
Alliance LB Dallas Holdings, LLC | Louisiana
Alliance LB Miami Holdings, LLC | Louisiana
Alliance Liftboats, LLC | Louisiana
Alliance Maritime Holdings, LLC | Louisiana
Alliance Offshore, LLC | Louisiana
Alliance Special Ventures Holdings, LLC | Louisiana
Alliance-Triton GOM Holdings, LLC | Delaware
Alliance Vessel Leasing, LLC | Louisiana
Cal Dive I-Title XI, Inc. | Texas
Deepwater Abandonment Alternatives, Inc. | Texas
Dickson Road Investments, LLC | Louisiana
Energy Resource Technology (U.K.) Limited | Scotland
ERT Camelot Limited | Scotland
Explorer DSV Holdings, LLC | Louisiana
Heavy Lift Holdings, LLC | Louisiana
Hedron Holdings, LLC | Louisiana
Helix Alliance Decom, LLC | Delaware
Helix do Brasil Serviços de Petróleo Ltda. | Brazil
Helix Energy Solutions (U.K.) Limited | Scotland
Helix Offshore Crewing Services Limited | Scotland
Helix Offshore Crewing Services PTE. Ltd. | Singapore
Helix Offshore Energy Services (Australia) Pty Ltd. | Australia
Helix Offshore Holdings Ltd. | Delaware
Helix Offshore International Holdings S.à r.l. | Grand Duchy of Luxembourg
Helix Offshore International, Inc. | Texas
Helix Offshore Ltd. | Cayman Islands
Helix Offshore Services A.S. | Norway
Helix Offshore Services Limited | Scotland
Helix Oil & Gas (U.K.) Limited | Scotland
Helix Property Corp. | Texas
Helix Q5000 Holdings LLC | Delaware
Helix Robotics Solutions, Inc. | Texas
Helix Robotics Solutions International Corp. | Texas
Helix Robotics Solutions Limited | Scotland
Helix Subsea Construction, Inc. | Delaware
Helix Well Ops Inc. | Texas
Helix Well Ops (U.K.) Limited | Scotland
Independence Hub, LLC (20% owned) | Delaware
Kommandor LLC | Delaware
Offshore Well Services, S. de R.L. de C.V. | Mexico
Patriot DSV Holdings, LLC | Louisiana
Subsea Technologies Group Limited | Scotland
Triton Diving Services, LLC | Louisiana
Whitney Clare Holdings, LLC | Louisiana
Whitney Liftboats, LLC | Louisiana
Whitney Maritime Holdings, LLC | Louisiana

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