German submarine U-704 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.
Commissioned on 18 November 1941 under the command of Kapitänleutnant Horst Wilhelm Kessler, U-704 carried out training operations as part of the 8th U-boat Flotilla until 30 June 1942.
German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-704 had a displacement of when at the surface and while submerged. She had a total length of , a pressure hull length of , a beam of , a height of , and a draught of . The submarine was powered by two Germaniawerft F46 four-stroke, six-cylinder supercharged diesel engines producing a total of for use while surfaced, two AEG GU 460/8âÂÂ27 double-acting electric motors producing a total of for use while submerged. She had two shafts and two propellers. The boat was capable of operating at depths of up to .
The submarine had a maximum surface speed of and a maximum submerged speed of . When submerged, the boat could operate for at ; when surfaced, she could travel at . U-704 was fitted with five torpedo tubes (four fitted at the bow and one at the stern), fourteen torpedoes, one SK C/35 naval gun, 220 rounds, and a C/30 anti-aircraft gun. The boat had a complement of between forty-four and sixty.
U-704 set out on its first patrol, a transit to its operational base at Saint-Nazaire on 30 June 1942. During this patrol, U-704 formed part of wolfpack "Wolf" which was to patrol between Iceland and Greenland, out of the range of allied air cover. On 26 July 1942, U-704 torpedoed the British freighter Empire Rainbow, part of convoy Convoy ON 113. Empire Rainbow had already been damaged by a torpedo from , and U-704s torpedo sank the freighter.
U-704 carried out a further four operational patrols under the command of Kessler from Saint Nazaire and La Pallice, sinking no further ships. U-704 did fire four torpedoes at the troopship Queen Elizabeth on 9 November 1942, with Kessler claiming a hit, although Queen Elizabeth was undamaged.
U-704 then served as a training submarine in the Baltic Sea for the rest of the war, and was scuttled at Vegesack on 30 April 1945.
U-704 took part in seven wolfpacks, namely: