|Ordered:||14 October 1941|
|Builder:||Blohm & Voss, Hamburg|
|Laid down:||19 December 1942|
|Launched:||17 September 1943|
|Commissioned:||4 November 1943|
|Fate:||Out of service, 29 August 1944|
|Class and type:||Type VIIC/41 submarine|
|Height:||9.60 m (31 ft 6 in)|
|Draught:||4.74 m (15 ft 7 in)|
|Complement:||44-52 officers & ratings|
|Operations:||1 patrol, 4–19 June 1944|
German Type VIIC/41 submarines were preceded by the heavier Type VIIC submarines. U-1000 had a displacement of 759 tonnes (747 long tons) when at the surface and 860 tonnes (850 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 Brown, Boveri & Cie GG UB 720/8 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-1000 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 2 cm (0.79 in) C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.
She was completed in Hamburg in November 1943, and after working up trials was moved to Egersund in Norway in June 1944. From there she conducted her only war patrol in the waters off Norway, in the North Sea and towards the Arctic Circle, but found no enemy ships to target, returning to Bergen without firing a shot. She did however manage to recover two Norwegian airmen of the British Royal Air Force, whose Mosquito aircraft had been shot down by U-804 two days before they were rescued from the sea.
On the 25 August 1944, as she passed the East Prussian town of Pillau on her way to Reval, she struck a sea mine laid by the Royal Air Force. The mine crippled the submarine, which limped into Pillau in a wrecked state. All the crew survived the blast, but the boat was totally unserviceable and was abandoned in Pillau, the crew being transferred to U-3523, on board which they were all killed the following year. RAF aircraft frequently mined German coastal waters, as they knew the routes used by German shipping, and could thus severely restrict German movement by sea with the use of air-dropped minefields.
- Gröner 1991, pp. 43-46.
- 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.
- Sharpe, Peter (1998). U-Boat Fact File. Great Britain: Midland Publishing. ISBN 1-85780-072-9.
- "The Type VII/C41 boat U-1000". German U-boats of WWII - uboat.net. Retrieved 6 December 2014.