German submarine U-717

German submarine U-717 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II. The submarine was laid down on 24 April 1942 at the H. C. Stülcken Sohn yard at Hamburg, launched on 20 February 1943, and commissioned on 19 May 1943 under the command of Oberleutnant zur See Siegfried von Rothkirch und Panthen. Attached to 5th U-boat Flotilla based at Kiel, U-717 completed her training period on 31 July 1944 and was assigned to front-line service.

Design
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-717 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-717 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
In the last days of World War II, U-717 was scuttled with other U-boats during Operation Regenbogen in Flensburg Firth on 5 May 1945 in position 54.81667°N, 9.45°W.