German submarine U-713

German submarine U-713 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 21 October 1941 at the H. C. Stülcken Sohn yard at Hamburg, launched on 24 September 1942, and commissioned on 29 December 1942 under the command of Oberleutnant zur See Henri Gosejacob.

Attached to 8th U-boat Flotilla based at Danzig, U-713 completed her training period on 30 June 1943 and was assigned to front-line service.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-713 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-713 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.

Fate
U-713 was missing since 24 February 1944 in the Norwegian Sea north-west of Narvik.

Previously recorded fate
While operating against convoy JW 57 on 24 February 1944, U-713 was spotted by a Swordfish from HMS Chaser. The destroyer HMS Keppel was directed towards the U-boat and attacked with depth charges, sinking U-713 in position 69.45°N, 4.88333°W.