German submarine U-964 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine built for service during World War II. A short-lived boat, U-964 is most noted for being one of three new boats ordered by the Kriegsmarine to attack Convoy ON 206 in the Western Approaches. To do this, the three boats had to travel a long distance on the surface during daylight hours in a region patrolled by Allied aircraft. This had fatal consequences for all U-boats involved. U-964 was built by the Blohm & Voss shipyards in Hamburg during 1942 as a Type VIIC boat designed to fight in the waters of the Northern Atlantic Ocean. Her construction was rapid and smooth, and following her completion in February 1943 she was taken for training and working-up patrols in the Baltic Sea and off the Norwegian coast. Her commander during this period was veteran submariner Oberleutnant zur See Emmo Hummerjohann, who was experienced in combat operations and was still in charge when she departed Bergen, Norway in early October 1943 for her maiden combat patrol in the North Atlantic. Design German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-964 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-964 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 one twin C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty. Service history War patrol Following her departure from Norway, she passed into the Atlantic and headed southwards towards the Western Approaches. After eleven days sailing, she was still well within range of Allied aircraft when she received