X0508 4 2026-01-26 0001451505 Transocean Ltd. RIG 0001750415 Adamson Keelan 1414 ENCLAVE PARKWAY HOUSTON TX 77077 true true false false PRESIDENT AND CEO 1 Registered Shares 2026-01-26 4 S 0 22846 5 D 1280869 D Registered Shares 2026-01-27 4 S 0 58687 5 D 1222182 D The sales reported in this Form 4 were effected pursuant to a Rule 10b5-1 trading plan adopted by the reporting person on March 28, 2025. The price reported in Column 4 is a weighted average price. These shares were sold in multiple transactions at prices ranging from $5.00 to $5.01, inclusive. The reporting person undertakes to provide Transocean Ltd. (the "Company"), any security holder of the Company, or the staff of the U.S. Securities and Exchange Commission, upon request, full information regarding the number of shares purchased at each separate price within the ranges set forth in this footnote (2) to this Form 4. /s/ Debra Kupferman by Power of Attorney 2026-01-28