German submarine U-991 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. Construction The U-991 was laid down on 30 October 1942 at the Blohm & Voss yard in Hamburg, Germany. She was launched on 24 June 1943 and commissioned on 29 July 1943 under the command of Oberleutnant zur See Diethelm Balke. Her U-boat emblem was a diving eagle. When she was completed, the submarine was long, with a beam of , a height of and a draft of . She was assessed at submerged. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced and two BBC GG UB 720/8 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The submarine was capable of operating at depths of up to , had a maximum surface speed of and a maximum submerged speed of .When submerged, the U-boat could operate for at and when surfaced, she could travel at . The submarine was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one deck gun (220 rounds) and a Flak M42 anti-aircraft gun. The boat had a complement of 44 to 57 men. Service history U-991 was used as a Training ship in the 5th U-boat Flotilla from 29 July 1943 until 31 August 1944 before serving in the 11th U-boat Flotilla for active service on 1 September 1944. Training and tests During U-991'''s service as a training ship, she completed a number of trainings and tests for the Kriegsmarine. Active Service During her active service, U-991 made 1 patrol and left Kristiansand on 15 October 1944. Her patrol lasted 73 days and U-991 patrolled the North Atlantic from Norway, around the United Kingdom and Ireland and also to France before returning to Bergen. She arrived in Bergen on 26 December 1944, which marked the end of her first and only patrol during World War II. In total, the U-991 spend 98 days at sea during her active service until 9 May 1945. Capture And End U-991 surrendered on 9 May 1945 at Bergen, Norway to the Allied Forces. The submarine was transferred from Bergen to Scapa Flow on 2 June 1945 and from Scapa Flow to Loch Ryan on 5 June 1945. She stayed in Loch