German submarine U-203

German submarine U-203 was a German Type VIIC submarine U-boat built for the Nazi German Kriegsmarine for service during World War II.

Built as 'Werk' 632 of Friedrich Krupp Germaniawerft AG in Kiel, she was laid down on 28 March 1940, launched on 4 January 1941 and commissioned on 18 February under Kapitänleutnant Rolf Mützelburg.

U-203 carried out eleven patrols with the first flotilla and is credited with sinking 21 ships for 94,270 GRT and damaging a further three for 17,052 GRT. She was a member of eleven wolfpacks.

She was sunk by British carrier-borne aircraft and a British warship southeast of Greenland in April 1943.

1st, 2nd and 3rd patrols
On 24 June 1941, nineteen days into her first patrol while en route from Kiel to St. Nazaire in France, U-203 attacked and sank the GRT 4,956 GRT British merchant ship Kinross, which was part of Convoy OB 336. Later that day, she attacked the 4,402 GRT Norwegian vessel Soløy, which was with Convoy HX 133.

Arriving at St. Nazaire on 29 June, the crew of U-203 stayed ashore for another eleven days before the boat made her second patrol. Seventeen days into it, she attacked Convoy OG 69 which was sailing to Gibraltar. On the 27th, U-203 sank the 2,475 GRT British merchant ship Hawkinge. The British Lapland and the Swedish Norita, also OG-69 merchant ships, were sunk the following day, adding a further 1,330 GRT and 1,516 GRT respectively to the U-boat's record.

Six days into her third patrol, on 26 September, the British ships Avoceta, Lapwing and the Norwegian Varanberg of Convoy HG 73 were sunk, destroying another 7,362 GRT of shipping.

4th, 5th and 6th patrols
Sixteen days into her fourth patrol, on 3 November, U-203 attacked and sank the Empire Gemsbuck (5,626 GRT) and the Everoja (4,830 GRT), British merchant ships of Convoy SC-52.

Twenty-one days into her fifth patrol on 15 January 1942, U-203 sank a small (632 GRT) Portuguese ship, the Catalina. Two days later, the Norwegian ship Octavian would also be sunk. Four torpedoes were fired at the Canadian ship North Gaspe, which survived the attack. One torpedo detonated close to the ship, but none actually hit.

U-203's sixth patrol resulted in a total loss of 14,232 GRT to the Allies and two additional ships damaged, including the British merchant vessels San Delfino and Empire Thrush. Damaged were the American tanker Henry F. Sinclair, Jr. and the Panamanian flagged tanker Stanvac Melbourne.

7th, 8th and 9th patrols
A seventh patrol beginning 4 June 1942, resulted in 32,985 GRT of shipping destroyed. The Brazilian Pedrinhas and the British MV Putney Hill were sunk on 26 June. Two days later the American Liberty Ship Sam Houston was torpedoed and then finished off with 43 rounds from the deck gun. The British Cape Verde was sunk on 9 July and the Panamanian tanker Stanvac Palembang on 11 July bringing the tally to five victories on this successful patrol.

The next 23 day sortie was unfruitful; however, the U-boat's commander, Rolf Mützelburg, died during this patrol on 11 September. Taking the opportunity to go swimming in the Atlantic southwest of the Azores, he dived from the conning tower and struck the deck with his head and shoulder when the U-boat lurched suddenly in the swell. The doctor from U-462, a 'Milk Cow' supply submarine, arrived the next day, but too late. Rolf Mützelburg was buried at sea on 12 September 1942 in position 36.23333°N, -31.35°W. He was replaced by Kptlt. Hermann Kottman, who served as captain for the remainder of U-203's career.

Her ninth patrol, beginning 15 October 1942 and terminating 6 November, yielded two further ships sunk. The British merchantmen Hopecastle and Corinaldo (5,178 and 7,131 GRT, respectively) were sunk on 29 October and 30 October while traveling with Convoy SL-125.

Loss
U-203 undertook two more patrols, both unsuccessful. On 25 April 1943 while south of Cape Farewell, Greenland she was sunk by depth charges in position 55.08333°N, -42.41667°W. She had been attacked by Fairey Swordfish aircraft operating from the British escort carrier HMS Biter (D97) and the British destroyer HMS Pathfinder. Ten men were killed, there were 38 survivors.

Summary of raiding history
U-203 sank 21 ships and damaged three others for a total of 111,322 GRT.