After an overhaul at Mare Island Naval Shipyard from 27 January–22 April, "Sailfish" returned to Pearl Harbor on 30 April. Departing Hawaii on 17 May for her eighth patrol, she stopped off to fuel at Midway Island and proceeded to her station off the east coast of Honshū. Several contacts were made but, because of bad weather, were not attacked. On 15 June, she encountered two freighters off Todo Saki, escorted by three subchasers. Firing a spread of three stern torpedoes, she observed one hit which stopped the "maru" dead in the water. "Sailfish" was driven down by the escort, but listened on her sound gear as "Shinju Maru" broke up and sank. Ten days later, she found a second convoy, three ships with a subchaser and, unusually, an aircraft, for escort. "Sailfish" once more fired three stern tubes, sinking "Iburi Maru"; in response, the subchaser, the aircraft, and three additional escorts, pinned her down in a gruelling depth charge attack lasting 10 hours and 98 charges but causing only slight damage. After shaking loose pursuit, she set course for Midway on 26 June, arriving there on 3 July.