German submarine U-31 was a Type VIIA U-boat of the Nazi German Kriegsmarine during World War II. She was laid down on 1 March 1936 as Werk 912, launched on 25 September and commissioned on 28 December 1936.
German submarine U-31 was a Type VIIA U-boat of the Nazi German Kriegsmarine during World War II. She was laid down on 1 March 1936 as Werk 912, launched on 25 September and commissioned on 28 December 1936.
German submarine U-31 was a Type VIIA U-boat of the Nazi German Kriegsmarine during World War II. She was laid down on 1 March 1936 as Werk 912, launched on 25 September and commissioned on 28 December 1936.