X0508 4 2026-03-01 0001451505 Transocean Ltd. RIG 0001240666 THIGPEN JEREMY D 1414 ENCLAVE PARKWAY HOUSTON TX 77077 true true false false Executive Chair 0 Registered Shares 2026-03-01 4 M 0 193518 6.25 A 2442643 D Registered Shares 2026-03-01 4 M 0 245640 6.25 A 2688283 D Registered Shares 2026-03-01 4 M 0 171821 6.25 A 2860104 D Registered Shares 2026-03-03 4 F 0 245556 6.12 D 2614548 D Restricted Units, which are 1-for-1 share equivalents, acquired on February 9, 2023, pursuant to the Issuer's long-term incentive plan. One third of such restricted units vested on March 1, 2026, resulting in the right of the reporting person to receive the registered shares. The amount of securities beneficially owned following the reported transaction reflects a prior transfer of shares to the reporting person's former spouse pursuant to a domestic relations order. Restricted Units, which are 1-for-1 share equivalents, acquired on February 8, 2024, pursuant to the Issuer's long-term incentive plan. One third of such restricted units vested on March 1, 2026, resulting in the right of the reporting person to receive the registered shares. The remaining restricted share units vest as follows: 245,640 on March 1, 2027. Restricted Units, which are 1-for-1 share equivalents, acquired on February 13, 2025, pursuant to the Issuer's long-term incentive plan. One third of such restricted units vested on March 1, 2026, resulting in the right of the reporting person to receive the registered shares. The remaining restricted share units vest as follows: 171,821 on March 1, 2027 and 171,822 on March 1, 2028. Shares sold upon vesting to satisfy tax withholding obligations. /s/ Debra Kupferman by Power of Attorney 2026-03-03