German submarine U-705

German submarine U-705 was a Type VIIC U-boat of the German Kriegsmarine during World War II.

Commissioned on 30 December 1941, she served with the 5th U-Boat Flotilla until 31 July as a training boat, and as a front boat of 66th Flotilla under the command of Kapitänleutnant Karl-Horst Horn, until her sinking on 3 September 1942.

Patrol History
Departing on her first and only patrol on 1 August 1942, U-705 left Kiel to encircle the British isles and turn back after crossing more than half of the Atlantic. On 15 August while driving some 550 miles south-east of Iceland, she caught sight of a number of vessels; Convoy SC 95, and the merchant ship Balladier.

Diving after first being seen, she would stay submerged for nearly four hours before firing a torpedo at the starboard side of the Balladier. Listing to the starboard side, the armed guards were unable to return fire on U-705, with the ship sinking after seven minutes.

On 24 August, the Norwegian corvette HNoMS Potentilla and the HMS Viscount of convoy ON 122 located U-705. Dropping five depth charges from the Viscount, along with a further ten from the Potentilla, the two were unable to cause damage to the boat. A further fifty-seven charges would be dropped at her and GS U-135 (1941), finally damaging her stern torpedo tube.

On 3 September, Armstrong Whitworth Whitleys of No. 77 Squadron RAF dropped depth charges at U-705, causing her to sink with all hands lost in the Bay of Biscay.