The Type II U-boat was a type of 50 German submarines used by the Kriegsmarine during World War II. It was developed and produced by the firms Deutsche Werke, Germaniawerft, and Flender Werke, in Kiel, northern Germany, in four versions: Type IIA, IIB, IIC, and IID. The first one, U-1, was launched in 1934 and entered service in 1935. It did not see combat action during the war as it was employed for training navy officers.
Developed from the Finnish submarine Vesikko, the Type II U-boat was characterized by its small size, being only 40 m in length and 4 m in width (beam) as it was served by a crew of 24 men. It was armed with only 5 torpedoes fired through 3 torpedo tubes. Its power plant consisted of two 700hp, 6-cylinder, MWM diesel engine, and two 402hp, electric motors. Its maximum speed was 13 knots on surface.