German submarine U-20 was a Type IIB U-boat of Nazi Germany's Kriegsmarine. Her keel was laid down on 1 August 1935, by Germaniawerft of Kiel as yard number 550. She was commissioned on 1 February 1936. During World War II, she conducted operations against enemy shipping.
German submarine U-22 was a Nazi German Type IIB U-boat which was commissioned in 1936 following construction at the Germaniawerft shipyards at Kiel. Her pre-war service was uneventful, as she trained crews and officers in the rapidly expanding U-boat arm of the Kriegsmarine following the abandonment of the terms of the Treaty of Versailles two years before.
German submarine U-10 was a Type IIB U-boat built before World War II for service in Nazi Germany's Kriegsmarine. As she was one of the first batch of boats built following the renunciation of the Treaty of Versailles, she was only capable of coastal and short cruising work. This led to her being reassigned to training duties after the Norwegian campaign of 1940 together with many of her sister boats.
German submarine U-16 was a Type IIB U-boat of Nazi Germany's Kriegsmarine that served during World War II. It was launched on 28 April 1936, under the command of Heinz Beduhn, with a crew of 23. Its last of four commanders was Horst Wellner.
German submarine U-23 was a Type IIB U-boat of Nazi Germany's Kriegsmarine, built in Germaniawerft, Kiel. She was laid down on 11 April 1936 and commissioned on 24 September.
German submarine U-24 was a Type IIB U-boat that was in service of Nazi Germany's Kriegsmarine during World War II. She was laid down on 21 April 1936 at the F. Krupp Germaniawerft in Kiel with yard number 554, launched on 24 September and commissioned into the Kriegsmarine on 10 October. Oberleutnant zur See Heinz Buchholz took command on 3 July 1937.
German submarine U-11 was a Type IIB U-boat built before World War II for service in Nazi Germany's Kriegsmarine. She was commissioned on 21 September 1935, with Kapitänleutnant Hans-Rudolf Rösing in command. She served in several training flotillas in her 10-year career, but sank or damaged no ships.
German submarine U-13 was a Type IIB U-boat of Nazi Germany's Kriegsmarine which was commissioned on 30 November 1936, following construction at the Deutsche Werke shipyards at Kiel. The first commander on board was Hans-Gerrit von Stockhausen. In her career she completed nine patrols, all while serving with the 1st U-boat Flotilla. The U-boat succeeded in sinking nine ships and damaging three more.
German submarine U-15 was a Type IIB U-boat of the Kriegsmarine. It was commissioned on 7 March 1936, following construction at the Deutsche Werke shipyards at Kiel. Its first commander was Werner von Schmidt. In its career, it completed five patrols, all while serving under the 1st U-boat Flotilla. It sank three ships.
German submarine U-17 was a Type IIB U-boat of Nazi Germany's Kriegsmarine. It was built in Germaniawerft, Kiel, where it was laid down on 1 July 1935 and commissioned on 3 December 1935, under the command of Werner Fresdorf.
German submarine U-18 was a Type IIB U-boat of Nazi Germany's Kriegsmarine during World War II. It was laid down 10 July 1935 and commissioned on 4 January 1936. It served in many U-boat flotillas during its service.
German submarine U-14 was a Type IIB U-boat of Nazi Germany's Kriegsmarine during World War II. It served with 3rd U-boat Flotilla from 18 January 1936 to 31 October 1939. U-14 completed six wartime patrols and sank nine ships totalling 12,344 GRT.
The German submarine U-8 was a Type IIB U-boat of Nazi Germany's Kriegsmarine, based at Kiel during World War II. It was one of the smaller versions, and was first launched on 16 July 1935. Its first commander was Harald Grosse. U-8 would have 18 commanders over the course of its service, the last being Jürgen Kriegshammer.
German submarine U-21 was a Type IIB U-boat of Nazi Germany's Kriegsmarine. Her keel was laid down 4 March 1936, by Germaniawerft of Kiel as yard number 551. She was commissioned on 3 August 1936. During World War II, she conducted operations against enemy shipping.
German submarine U-121 was a long-lived Type IIB U-boat built during World War II for service in Nazi Germany's Kriegsmarine. U-121 spent the entire war as a training vessel and was scuttled at the end of the conflict.
German submarine U-152 was a Type IID U-boat of Nazi Germany's Kriegsmarine during World War II. Her keel was laid down on 6 July 1940 by Deutsche Werke in Kiel as yard number 281. She was launched on 14 December 1940 and commissioned on 29 January 1941 with Kapitänleutnant Peter-Erich Cremer in command.
German submarine U-2519 was a Type XXI U-boat of Nazi Germany's Kriegsmarine, built for service in World War II. The submarine was laid down on 24 August 1944 at the Blohm & Voss yard at Hamburg, launched on 13 October 1944, and commissioned on 15 November 1944 under the command of Korvettenkapitän Peter-Erich Cremer, who commanded her until February 1945. U-2519 conducted no patrols and was scuttled on 3 May 1945 in Kiel. The wreck was broken up.
German submarine U-742 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine built for service during World War II. Her keel was laid down on 12 May 1942 by Schichau-Werke of Danzig. She was commissioned on 1 May 1943 with Kapitänleutnant Heinz Schwassmann in command.
German submarine U-740 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine built for service during World War II. Her keel was laid down on 26 April 1942 by Schichau-Werke of Danzig. She was commissioned on 27 March 1943 with Oberleutnant zur See Günther Stark in command.
German submarine U-749 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine built for service during World War II. Her keel was laid down on 28 September 1942 by Schichau-Werke of Danzig. She was commissioned on 14 August 1943 with Tenente di vascello Alberto Longhi in command.
Nazi Germany 
