USS S-31 (SS-136) - Fifth War Patrol

Fifth War Patrol

On her fifth war patrol, 13 October to 8 November, S-31 moved into the Kuril Islands. She arrived on station on 20 October. Two days later, she was off Paramushiro and patrolled the traffic lanes in the northern Paramushiro-Shumushu area until 24 October. She then headed for Onekotan Strait. The next day, she hunted in the northeast approaches to that passage. On the morning of the 26th, she closed the Paramushiro coast; and, at 0825, she sighted a target in Otomae Wan and began her approach. At 0922, she launched two torpedoes; the target, the 2,864-ton cargoman KEIZAN MARU, sank in the anchorage. At 0923, S-31 went aground on a reef. She backed off and went ahead. Between 0928 and 0955, she grounded several more times at periscope depth. At 1000, she reached deep water and cleared the area unpursued. That night, she transited Onekotan Strait through "monstrous seas;" and, on 27 October, she commenced hunting along the west coast of Paramushiro. With November, however, her fuel supply became the critical factor; and, on 2 November, she turned for home.

S-31 arrived at Dutch Harbor on 8 November. Three days later, she sailed for San Diego where she provided training services for the West Coast Sound School from 27 November 1942 to 3 January 1943. Refit followed into February. Toward the end of that month, she moved west to Hawaii. There, her four-inch (102 mm) gun was replaced by a three-inch (76 mm) gun, and further training exercises were conducted. On 11 March, she continued west on her sixth war patrol.