German submarine U-663

German submarine U-663 was a Type VIIC U-boat built for Nazi Germany's Kriegsmarine for service during World War II. She was laid down on 31 March 1941 by Deutsche Werft, Hamburg as yard number 812, launched on 26 March 1942 and commissioned on 14 May 1942 under Kapitänleutnant Heinrich Schmid.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-663 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-663 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 a 2 cm C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.

Service history
The boat's career began with training at 5th U-boat Flotilla on 14 May 1942, followed by active service on 1 October 1942 as part of the 11th Flotilla. After only one month, she transferred to the 9th Flotilla on 1 November 1942, for the remainder of her service.

In 3 patrols she sank 2 merchant ships, for a total of.

Wolfpacks
U-663 took part in four wolfpacks, namely:
 * Drachen (22 November – 3 December 1942)
 * Panzer (3 – 9 December 1942)
 * Büffel (9 – 14 December 1942)
 * Seeteufel (21 – 30 March 1943)

Fate
U-663 was sunk on 8 May 1943 in the Bay of Biscay in position 46.83333°N, -10°W, by depth charges from a No. 10 Squadron RAAF Sunderland. All hands were lost.