were preceded by the shorter Type VIIB submarines. U-305 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 Garbe, Lahmeyer & Co. RP 137/c 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-305 was fitted with five torpedo tubes, fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and two twin C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
Service history
The boat's service life began with training with the 8th U-boat Flotilla in September 1942. She was then transferred to the 1st flotilla for operations on 1 March.
1st patrol
The submarine's first patrol began with her departure from Kiel on 27 February 1943. She passed through the gap between Iceland and the Faroe Islands and into the north Atlantic Ocean. On 17 March she sank Port Auckland and Zouave southeast of Cape Farewell, the latter foundering in five minutes. The boat arrived in Brest in occupied France, on 12 April 1943.
2nd and 3rd patrols
U-305s second foray was relatively uneventful, starting and finishing in Brest, as would all her remaining patrols, on 12 May and 1 June 1943. On her third sortie, she sank on 20 September 1943. The Canadian warship was one of the first victims of a GNAT acoustic torpedo.
4th patrol and loss
The boat's final patrol commenced on 8 December 1943. She successfully attacked southwest of Ireland. This ship sank in just two minutes, with the loss of 83 men. U-305 was lost in January 1944. Fifty-one men died; there were no survivors. U-305 was originally thought to have been sunk by the British destroyer and the frigate at on 17 January 1944. but recent research suggests this attack sank, and U-305 was lost by unknown cause, possibly a victim of one of her own torpedoes.