German submarine U-683

German submarine U-683 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 23 December 1942 at the Howaldtswerke yard at Hamburg, launched on 7 March 1944, and commissioned on 30 May 1944 under the command of Oberleutnant zur See Günter Keller.

Attached to 31st U-boat Flotilla based at Wesermünde, U-683 completed her training period on 31 December 1944 and was assigned to front-line service.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-683 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 Siemens-Schuckert GU 343/38–8 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-683 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), one 3.7 cm Flak M42 and two twin 2 cm C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.

Service history
On the first and final war patrol, U-683 was last heard from on 20 February 1945 en route to the assigned patrol area off Cherbourg. The U-boat was declared missing on 3 April 1945.

Previously recorded fate
The U-683 was recorded missing on 12 March 1945 after it was sunk in the English Channel the same day by depth charges from British frigate HMS Loch Ruthven and British sloop HMS Wild Goose. This attack was probably against the wreck of U-247.