German submarine U-243

German submarine U-243 was a Type VIIC U-boat of Nazi Germany's Kriegsmarine during World War II.
An order was placed for U-243 on 10 April 1941 and construction began on 28 October 1942 at Friedrich Krupp Germaniawerft, Kiel, as yard number 677. She was launched the following year on 2 September 1943 and commissioned on 2 October 1943 under the command of Oberleutnant zur See Hans Märtens. Three days into her only patrol, she shot a German aircraft down.
She was sunk in the Bay of Biscay on 8 July 1944.

Design

German Type VIIC submarines were preceded by the shorter Type VIIB submarines. U-243 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 460/8–27 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-243 was fitted with five torpedo tubes, fourteen torpedoes, one SK C/35 naval gun,, one Flak M42 and two twin C/30 anti-aircraft guns. The boat had a complement of between forty-four and sixty.

Her only patrol was preceded by a short voyage from Kiel to Flekkefjord in southern Norway in May 1944. On 11 June 1944, she mistakenly shot down a German Junkers Ju 88 aircraft southwest of Bergen while making for that city.
She passed through the gap between Iceland and the Faroe Islands and steamed south, heading for the French Atlantic ports.
She was attacked and sunk by a Sunderland flying boat of No. 10 Squadron RAAF in the Bay of Biscay on 8 July 1944. Eleven men died; there were 38 survivors.