German submarine U-243

German submarine U-243 was a Type VIIC U-boat of the Nazi German Kriegsmarine during World War II.

An order was placed for U-243 on 10 April 1941 and construction began on 28 October 1942 at Germaniawerft, Kiel, as 'werk' 677. She was launched the following year on 2 September 1943 and commissioned on 2 October under the command of Oberleutnant Hans Märtens.

Three days into her only patrol, she shot a German aircraft down.

She was sunk in the Bay of Biscay in July 1944

Service record
Her only patrol was preceded by a short voyage from Kiel to Flekkefjord in southern Norway in May 1944. On 11 June, she mistakenly shot a German JU 88 down 40 mi 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.