History
Nazi Germany
Name	U-743
Ordered	5 June 1941
Builder	Schichau-Werke, Danzig
Yard number	1546
Laid down	30 May 1942
Launched	11 March 1943
Commissioned	15 May 1943
Fate	Missing since 22 August 1944
General characteristics
Class and type	Type VIIC submarine
Displacement	769 tonnes (757 long tons) surfaced 871 t (857 long tons) submerged
Length	67.10 m (220 ft 2 in) o/a 50.50 m (165 ft 8 in) pressure hull
Beam	6.20 m (20 ft 4 in) o/a 4.70 m (15 ft 5 in) pressure hull
Height	9.60 m (31 ft 6 in)
Draught	4.74 m (15 ft 7 in)
Installed power	2,800–3,200 PS (2,100–2,400 kW; 2,800–3,200 bhp) (diesels) 750 PS (550 kW; 740 shp) (electric)
Propulsion	2 shafts 2 × diesel engines 2 × electric motors
Speed	17.7 knots (32.8 km/h; 20.4 mph) surfaced 7.6 knots (14.1 km/h; 8.7 mph) submerged
Range	8,500 nmi (15,700 km; 9,800 mi) at 10 knots (19 km/h; 12 mph) surfaced 80 nmi (150 km; 92 mi) at 4 knots (7.4 km/h; 4.6 mph) submerged
Test depth	230 m (750 ft) Crush depth: 250–295 m (820–968 ft)
Complement	4 officers, 40–56 enlisted
Armament	5 × 53.3 cm (21 in) torpedo tubes (four bow, one stern) 14 × torpedoes 1 × 8.8 cm (3.46 in) deck gun (220 rounds) 2 × twin 2 cm (0.79 in) C/30 anti-aircraft guns
Service record
Part of:	8th U-boat Flotilla 15 May 1943 – 30 June 1944 1st U-boat Flotilla 1 July – 22 August 1944
Identification codes:	M 51 797
Commanders:	Oblt.z.S. Helmut Kandzior 15 May 1943 – 22 August 1944
Operations:	1 patrol: a. 18 – 20 August 1944 b. 21 – 22 August 1944
Victories:	None

German submarine U-743 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine built for service during World War II. Her keel was laid down on 30 May 1942 by Schichau-Werke of Danzig. She was commissioned on 15 May 1943 with Oberleutnant zur See Helmut Kandzior in command.

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-743 had a displacement of 769 tonnes (757 long tons) when at the surface and 871 tonnes (857 long tons) while submerged.^[1] 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 AEG GU 460/8–27 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).^[1]

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).^[1] 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-743 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, and two twin 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.^[1]

On 20 August 1944 U-743 entered Trondheim for schnorkel repairs. She left the next day and was never heard from again. On 10 September 1944 U-743 was declared missing.

U-743 was originally thought to have been sunk on 9 September 1944 at position 55°27′N 11°25′W / 55.45°N 11.41°W / 55.45; -11.41 by depth charges from HMS Portchester Castle and HMS Helmsdale. This attack actually resulted in the sinking of U-484.

• Helgason, Guðmundur. "The Type VIIC boat U-743". German U-boats of WWII - uboat.net. Retrieved 25 February 2016.