|Ordered||20 January 1941|
|Laid down||8 April 1942|
|Launched||15 May 1943|
|Commissioned||3 July 1943|
|Fate||Scuttled on 5 May 1945 near the Fyn Islands in Flensburger Förde|
|Class and type||Type VIIC submarine|
|Height||9.60 m (31 ft 6 in)|
|Draught||4.74 m (15 ft 7 in)|
|Complement||4 officers, 40–56 enlisted|
German submarine U-393 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.
She did not carry out any patrols and did not sink or damage any ships.
She was scuttled on 5 May 1945 in Flensburger Förde.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-393 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged. She had a total length of 67.10 m (220 ft 2 in), a pressure hull length of 50.50 m (165 ft 8 in), a beam of 6.20 m (20 ft 4 in), a height of 9.60 m (31 ft 6 in), and a draught of 4.74 m (15 ft 7 in). The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of 2,800 to 3,200 metric horsepower (2,060 to 2,350 kW; 2,760 to 3,160 shp) for use while surfaced, two Garbe, Lahmeyer & Co. RP 137/c double-acting electric motors producing a total of 750 metric horsepower (550 kW; 740 shp) for use while submerged. She had two shafts and two 1.23 m (4 ft) propellers. The boat was capable of operating at depths of up to 230 metres (750 ft).
The submarine had a maximum surface speed of 17.7 knots (32.8 km/h; 20.4 mph) and a maximum submerged speed of 7.6 knots (14.1 km/h; 8.7 mph). When submerged, the boat could operate for 80 nautical miles (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph); when surfaced, she could travel 8,500 nautical miles (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph). U-393 was fitted with five 53.3 cm (21 in) torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one 8.8 cm (3.46 in) SK C/35 naval gun, (220 rounds), one 3.7 cm (1.5 in) Flak M42 and two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
The submarine was laid down on 8 April 1942 at the Howaldtswerke (yard) at Flensburg as yard number 25, launched on 15 May 1943 and commissioned on 3 July under the command of Oberleutnant zur See Alfred Radermacher.
She served with the 5th U-boat Flotilla from 3 July 1943 and the 24th flotilla as a trials vessel from 1 November 1944. She then came under the 5th flotilla once more from 1 April 1945.
U-393 was bombed by US aircraft in Geltinger Bucht on 4 May 1945. Two men were killed; there were an unknown number of survivors. She was scuttled the following day in the Flensburger Förde near the Fyn Islands.