The Shishumar-class submarines are diesel-electric attack submarines, currently in active service with the Indian Navy. These submarines are an Indian variant of the Type 209 submarines developed by the German yard Howaldtswerke-Deutsche Werft under the internal designation "Type 1500". The first two vessels were built by HDW at Kiel, Germany, while the remainder were built by Mazagon Dock Limited, at Mumbai, India, under a technology transfer agreement. The submarines were commissioned between 1986 and 1994. These submarines have a displacement of 1,660 tons when surfaced, a speed of 22 knots (41 km/h; 25 mph), and a complement of 40 including eight officers.