Japanese escort Shimushu

Shimushu (占守) was lead ship of its class, the foundation of all of Japan's kaibokan.

Shimushu participated in the landings in Thailand, escorting the 55th IJA Infantry Division to landings at Nakhon on 8 December 1941. Shimushu also escorted various other invasion convoys to Malaya, Sumatra, and Palembang. Using her sonar, she located the British battlecruiser HMS Repulse (1916) on 29 January 1942, being the first ship to locate the submerged wreck.

Shimushu participated in the HI-40 convoy disaster of 19-24 February 1944, in which all six oilers that were escorted by her — and only her, as she was the lone escort vessel — were torpedoed and sunk by the American submarines USS Grayback (SS-208) and USS Jack (SS-259). After that convoy disaster, the Naval General staff discontinued assigning only one escort to convoys and organized larger convoys with more escorts.

Shimushu participated in the TA No. 2 and 3, the Japanese effort to hold Leyte island, and claimed one of the five B-25 Mitchell medium bombers lost in the first wave. On 25 November, Shimushu was torpedoed by USS Haddo (SS-255) and lost her bow, and was repaired by 20 January 1945.

Shimushu spent more than a year on repatriation duty and was ceded to the Soviet Union on 5 July 1947.

Served in Soviet Pacific Ocean Fleet as patrol ship EK-31 (1947), dispatch ship PS-25 (1948), repair ship PM-74 (1957). Decommissioned on May 16, 1959 and scrapped.