Diving planes, also known as hydroplanes, are control surfaces found on a submarine which allow the vessel to pitch its bow and stern up or down to assist in the process of submerging or surfacing the
The port bow plane of the Soviet-era submarine B-39
The F-class submarines were a group of four submarines designed for the United States Navy by Electric Boat in 1909. F-1 and F-2 were built by Union Iron Works, in San Francisco, while F-3 and F-4 wer
These boats are (from front to back): USS F-4, ex-Skate, F-2, ex-Barracuda, F-3, ex-Pickerel, and F-1, ex-Carp, in Honolulu, Territory of Hawaii, in 1914. Note the "fish" flags and 13-star "boat" ensigns flown by these submarines.