German submarine U-621 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 1 July 1941 by Blohm & Voss in Hamburg as yard number 597, launched on 19 March 1942 and commissioned on 7 May 1942 under Kapitänleutnant Horst Schünemann. Design German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-621 had a displacement of when at the surface and while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two Brown, Boveri & Cie GG UB 720/8 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to . The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-621 was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and a C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty. Service history The boat's service began on 7 May 1942 for training as part of the 8th U-boat Flotilla. After training was completed she transferred to the 9th flotilla on 1 October 1942 for active service. In ten patrols she sank four merchant ships for a total of , plus one auxiliary warship. She also damaged two more ships. Wolfpacks She took part in eleven wolfpacks, namely: Panther (10 – 16 October 1942) Puma (16 – 29 October 1942) Raufbold (11 – 18 December 1942) Hartherz (3 – 7 February 1943) Ritter (11 – 26 February 1943) Burggraf (4 – 5 March 1942) Raubgraf (7 – 15 March 1943) Amsel 1 (3 – 6 May 1943) Elbe (7 – 10 May 1943) Elbe 2 (10 – 14 May 1943) Mosel (19 – 24 May 1943) Fate She was sunk by depth charges dropped by three Royal Canadian Navy destroyers, , and on 18 August 1944 near La Rochelle at position . Summary of raiding history References