The Type II U-boat was designed by Nazi Germany as a coastal U-boat, modeled after the CV-707 submarine, which was designed by the Dutch front company NV Ingenieurskantoor voor Scheepsbouw Den Haag (I.v.S) (set up by Germany after World War I in order to maintain and develop German submarine technology and to circumvent the limitations set by the Treaty of Versailles) and built in 1933 by the Finnish Crichton-Vulcan shipyard in Turku, Finland.

Its primary role was found to be in the training schools, preparing new German naval officers for command.

Germany was stripped of its U-boats by the Treaty of Versailles at the end of World War I, but in the late 1920s and early 1930s began to rebuild its armed forces.

The pace of rearmament accelerated under Adolf Hitler, and the first Type II U-boat was laid down on 11 February 1935.

Known as the Einbaum ("dugout canoe"), it had some advantages over larger boats, chiefly its ability to work in shallow water, dive quickly, and increased stealth due to the low conning tower.

However, it had a shallower maximum depth, short range, cramped living conditions, and carried fewer torpedoes.

Most Type IIs only saw operational service during the early years of the war, thereafter remaining in training bases.

Six were stripped down to their hulls, transported by river and truck to Linz (on the Danube), and reassembled for use in the Black Sea against the Soviet Union.

The additional diesel tanks beneath the control room were further enlarged, extending the range to 1,900 nautical miles at 12 knots.

The range was nearly doubled to 3,450 nmi (6,390 km; 3,970 mi) at 12 knots (22 km/h; 14 mph) and enabled the Type II to conduct longer operations around the British Isles.