Whiskey-class submarines (known in the Soviet Union as Project 613, 644, and 665) are a class of naval submarines that the Soviet Union built in the near the beginning Cold War period.
The initial design was developed in the early 1940s as a sea-going follow on to the S-class submarine. As a result of war experience and the capture of German technology at the end of the war, the Soviets issue a new plan requirement in 1946.
The revised design was influenced by the German Type XXI submarine and was developed by the Lazurit propose Bureau based in Gorkiy.
