The submarine refitted at Pearl Harbor once more between 11 February and 6 March 1944, then sailed for her eighth war patrol, off Truk in the Caroline Islands. Prevented from launching attacks through most of the eighth patrol because of her assignment as lifeguard for carrier air strikes on targets in the Carolines, Finback contacted a six-ship convoy on 12 April, noting three escorts. She attacked four of the ships before a counter-attack sent her deep. On 16 April, while making a reconnaissance of Oroluk Atoll, she fired on a partially submerged steamer and a lookout tower on the atoll. Three days later, she sank one of a group of sampans, then sailed for refit at Pearl Harbor from 1 May to 30 May.
