A vessel lying about 30 meters below the ocean surface in a port of Chichijima island of the Ogasawara Islands, Tokyo, is likely that of the Submarine Chaser No. 50, which was sunk by US forces in July 1944.
Submarine Chaser No. 50 was a 50-meter-long vessel constructed in 1943, according to documents at the National Institute for Defence Studies and other sources. It was engaged in an escort mission for a supply fleet heading to island locations in the Pacific Ocean and it rescued about 800 people from attacks on Japanese vessels off Saipan when the island had nearly fallen to US forces.
Submarine chasers located submarines and attacked them with depth charges. The Imperial Japanese Navy used submarine chasers in World War II mainly to escort fleets with vessels carrying people and supplies and the coast guard.
Details of the sunken vessel in Futami Port of Chichijima island were not well known as diving in the area had been restricted by fish farms in the port.
After the fish farms were removed in December, The Yomiuri Shimbun took photos of the vessel with the assistance of the Ogasawara Islands fisheries cooperative association.