|Ordered:||5 June 1941|
|Builder:||Bremer Vulkan, Bremen-Vegesack|
|Laid down:||1 July 1942|
|Launched:||6 March 1943|
|Commissioned:||14 April 1943|
|Fate:||Scuttled, southeast of Greenland, November 1943|
|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|
|Operations:||One patrol: 28 November – 21 December 1943|
The submarine was laid down on 1 July 1942 at the Bremer Vulkan yard at Bremen-Vegesack as yard number 49. She was launched on 6 March 1943 and commissioned on 14 April under the command of Oberleutnant zur See Günter Scholz.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-284 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 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).
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-284 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.
U-284 served with the 8th U-boat Flotilla for training from April to October 1943 and operationally with the 9th flotilla from 1 November. She carried out one patrol, sinking no ships. She was a member of one wolfpack.
The boat's only patrol began with her departure from Kiel on 13 January 1944. She passed between Iceland and the Faroe Islands and into the Atlantic Ocean. She was scuttled southeast of Greenland on 21 November 1943, after sustaining sea damage. Her crew were taken off by U-629 and taken to Brest in occupied France, arriving on 5 January 1944.
- Busch, Rainer; Röll, Hans-Joachim (1999). German U-boat commanders of World War II : a biographical dictionary. Translated by Brooks, Geoffrey. London, Annapolis, Md: Greenhill Books, Naval Institute Press. ISBN 1-55750-186-6.
- Busch, Rainer; Röll, Hans-Joachim (1999). Deutsche U-Boot-Verluste von September 1939 bis Mai 1945 [German U-boat losses from September 1939 to May 1945]. Der U-Boot-Krieg (in German). IV. Hamburg, Berlin, Bonn: Mittler. ISBN 3-8132-0514-2.
- Gröner, Erich; Jung, Dieter; Maass, Martin (1991). U-boats and Mine Warfare Vessels. German Warships 1815–1945. 2. Translated by Thomas, Keith; Magowan, Rachel. London: Conway Maritime Press. ISBN 0-85177-593-4.
- Kemp, Paul (1999). U-Boats Destroyed - German Submarine Losses in the World Wars. London: Arms & Armour. ISBN 1-85409-515-3.
- Helgason, Guðmundur. "The Type VIIC boat U-284". German U-boats of WWII - uboat.net. Retrieved 26 December 2014.
- Hofmann, Markus. "U 284". Deutsche U-Boote 1935-1945 - u-boot-archiv.de (in German). Retrieved 26 December 2014.