German submarine U-307

German submarine U-307 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The U-boat was laid down on 5 November 1941, and commissioned on 18 November 1942.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-307 had a displacement of 769 t when at the surface and 871 t while submerged. She had a total length of 67.10 m, a pressure hull length of 50.50 m, a beam of 6.20 m, a height of 9.60 m, and a draught of 4.74 m. The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2800 to 3200 PS for use while surfaced, two Garbe, Lahmeyer & Co. RP 137/c double-acting electric motors producing a total of 750 PS for use while submerged. She had two shafts and two 1.23 m propellers. The boat was capable of operating at depths of up to 230 m.

The submarine had a maximum surface speed of 17.7 kn and a maximum submerged speed of 7.6 kn. When submerged, the boat could operate for 80 nmi at 4 kn; when surfaced, she could travel 8500 nmi at 10 kn. U-307 was fitted with five 53.3 cm torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm SK C/35 naval gun, 220 rounds, and two twin 2 cm C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.

Service history
Despite carrying out 13 war patrols between July 1943 and April 1945, U-307 sank only two vessels; the 7,176 GRT American Liberty ship SS William S. Thayer on 30 April 1944, fifty miles south of Bear Island, and the 50 GRT Norwegian Army motor boat Lennox in Van Mijenfjorden, Spitsbergen, on 18 August 1944.

In September 1944, together with the supply ship Carl J. Busch, U-307 transported the men of Operation Haudegen, a German military meteorological mission, to Svalbard.

Wolfpacks
U-307 took part in twelve wolfpacks, namely:
 * Wiking (5 September – 8 October 1943)
 * Monsun (3 October – 23 November 1943)
 * Eisenbart (28 October – 8 December 1943)
 * Boreas (28 February – 10 March 1944)
 * Thor (17 – 26 March 1944)
 * Donner (17 – 20 April 1944)
 * Donner & Keil (20 April – 3 May 1944)
 * Grimm (31 May - 6 June 1944)
 * Trutz (8 June – 10 July 1944)
 * Rasmus (6 – 13 February 1945)
 * Hagen (13 – 21 March 1945)
 * Faust (21 – 29 April 1945)

Fate
U-307 was sunk on 29 April 1945 in the Barents Sea near Murmansk, Russia, in position 69.4°N, 33.73333°W by depth charges from the British Loch class frigate HMS Loch Insh (K433). There were 37 dead and 14 survivors.