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Your Vote Counts! TRANSOCEAN LTD. TURMSTRASSE 30 CH-6312 STEINHAUSEN SWITZERLAND TRANSOCEAN LTD. 2024 Annual General Meeting Vote by 11:59 P.M. EDT May 15, 2024 / 5:59 A.M. Swiss time May 16, 2024 Meeting Date May 16, 2024 6:30 p.m. Swiss time Parkhotel Zug Industriestrasse 14 6304 Zug, Switzerland Smartphone users Point your camera here and vote without entering a control number For complete information and to vote, visit www.ProxyVote.com Control # V40587-P06727 You invested in TRANSOCEAN LTD. and it’s time to vote! You have the right to vote on proposals being presented at the Annual General Meeting. This is an important notice regarding the availability of proxy material for the shareholder meeting to be held on May 16, 2024. Get informed before you vote View the Combined Document online OR you can receive a free paper or email copy of the material(s) by requesting prior to April 26, 2024. If you would like to request a copy of the material(s) for this and/or future shareholder meetings, you may (1) visit www.ProxyVote.com, (2) call 1-800-579-1639 or (3) send an email to sendmaterial@proxyvote.com. If sending an email, please include your control number (indicated below) in the subject line. Unless requested, you will not otherwise receive a paper or email copy.

THIS IS NOT A VOTABLE BALLOT This is an overview of the proposals being presented at the upcoming shareholder meeting. Please follow the instructions on the reverse side to vote on these important matters. Vote at www.ProxyVote.com Prefer to receive an email instead? While voting on www.ProxyVote.com, be sure to click “Delivery Settings”. V40588-P06727 Voting Items Board Recommends 1. Approval of (A) the 2023 Annual Report, Including the Audited Consolidated Financial Statements of Transocean Ltd. for Fiscal Year 2023 and the Audited Statutory Financial Statements of Transocean Ltd. for Fiscal Year 2023, (B) the Swiss Statutory Compensation Report for Fiscal Year 2023 and (C) the Swiss Statutory Report on Non-Financial Matters for Fiscal Year 2023 1A Approval of the 2023 Annual Report, Including the Audited Consolidated Financial Statements of Transocean Ltd. for Fiscal Year 2023 and the Audited Statutory Financial Statements of Transocean Ltd. for Fiscal Year 2023 For 1B Approval of the Swiss Statutory Compensation Report for Fiscal Year 2023 For 1C Approval of the Swiss Statutory Report on Non-Financial Matters for Fiscal Year 2023 For 2. Discharge of the Members of the Board of Directors and the Executive Management Team from Liability for Activities During Fiscal Year 2023 For 3. Appropriation of the Accumulated Losses for Fiscal Year 2023 For 4. Approval of Shares Authorized for Issuance For 5. Reelection of 10 Directors, Each for a Term Extending Until Completion of the Next Annual General Meeting 5A Glyn A. Barker For 5B Vanessa C.L. Chang For 5C Frederico F. Curado For 5D Chadwick C. Deaton For 5E Domenic J. “Nick” Dell’Osso, Jr. For 5F Vincent J. Intrieri For 5G Samuel J. Merksamer For 5H Frederik W. Mohn For 5I Margareth Øvrum For 5J Jeremy D. Thigpen For 6. Reelection of Chadwick C. Deaton as the Chair of the Board of Directors for a Term Extending Until Completion of the Next Annual General Meeting For 7. Reelection of the Members of the Compensation Committee, Each for a Term Extending Until Completion of the Next Annual General Meeting 7A Glyn A. Barker For 7B Vanessa C.L. Chang For 7C Samuel J. Merksamer For 8. Reelection of Schweiger Advokatur / Notariat as the Independent Proxy for a Term Extending Until Completion of the Next Annual General Meeting For 9. Appointment of Ernst & Young LLP as the Company’s Independent Registered Public Accounting Firm for Fiscal Year 2024 and Reelection of Ernst & Young Ltd, Zurich, as the Company’s Auditor for a Further One Year Term For 10. Advisory Vote to Approve Named Executive Officer Compensation for Fiscal Year 2024 For 11. Prospective Vote on the Maximum Compensation of (A) the Board of Directors and (B) the Executive Management Team 11A Ratification of the Maximum Aggregate Amount of Compensation of the Board of Directors for the Period Between the 2024 Annual General Meeting and the 2025 Annual General Meeting For 11B Ratification of the Maximum Aggregate Amount of Compensation of the Executive Management Team for Fiscal Year 2025 For 12. Approval of (A) Redenominating the Currency of the Company’s Share Capital from Swiss Francs to U.S. Dollars and (B) Reducing the Par Value of the Company’s Shares 12A Approval of Redenominating the Currency of the Company’s Share Capital from Swiss Francs to U.S. Dollars For 12B Approval of Reducing the Par Value of the Company’s Shares For 13. Approval of (A) Amendment and Restatement of Transocean Ltd. 2015 Long-Term Incentive Plan and (B) Capital Authorization for Share-Based Incentive Plans 13A Approval of Amendment and Restatement of Transocean Ltd. 2015 Long-Term Incentive Plan For 13B Approval of Capital Authorization for Share-Based Incentive Plans For