Buka Island
While steaming through driving rain off New Ireland and west of Buka Island, "Okinoshima", which had been damaged by airplanes from "Yorktown" during the invasion of Tulagi on 4 May 1942, was torpedoed at 04:52 by the United States Navy submarine (Commander Oliver G. Kirk) and severely damaged. The invasion force's escorts closed "S-42" and depth charged the area until 1130, causing damage. The submarine left the area to return to base at Moreton Bay, Brisbane. Rear Admiral Shima transferred his flag to "Yūzuki" southwest of Buka Island, Bougainville. At 06:40, "Okinoshima" capsized under tow by "Mochizuki" in St. George's Channel at .