German submarine U-2551 was a Type XXI U-boat of Nazi Germany's Kriegsmarine during World War II. The Elektroboote submarine was laid down on 8 December 1944 at the Blohm & Voss yard at Hamburg, launched on 31 March 1945, and commissioned on 24 April 1945 under the command of Kapitänleutnant Gerhard Schaar. With the end of the war near, training on U-boats had dropped to a minimum due to lack of fuel, falling morale and the effectiveness of allied attacks on U-boat construction and preparation. The exception to this were the new Type XXI boats, which continued to train in the Baltic Sea.