JDS Oyashio (SS-511)

Oyashio (SS-511) was a submarine of the Japan Maritime Self-Defense Force, named after the Oyashio Current, a cold current that comes down through the Bering Strait.

Development
Following the loan of the Gato-class submarine USS Mingo (SS-261) as an underwater target in 1955, the Japan Maritime Self-Defense Force proposed the construction of three new classes of submarine, of 250, 500 and 1000 tons. In the end only the third of these classes was built, and the final weight grew to 1140 tons. Having had a vast submarine fleet before and during World War II, the Japanese had built no subs for over ten years, so JDS Oyashio was based on the wartime Imperial Japanese Navy I-201 with some US innovations. Laid down on 25 December 1957, and launched on 25 May 1959, Oyashio was commissioned on 30 June 1960.

Service history
On 1 August 1962 Oyashio was assigned to Subron 1, Kure district. In June–August 1963 she visited Pearl Harbor. Assigned to Subron 2, Submarine Flotilla 1 on 1 February 1965. Assigned to Submarine Flotilla 1 on 31 March 1975. Oyashio was finally decommissioned on 30 September 1976.