German submarine U-103 (1940)

The boat entered the Atlantic via the gap between the Faroe and Shetland Islands. Her first victory was sinking Nina Borthen in mid-ocean on 6 October. After being hit by a torpedo, the ship developed a list, which the crew corrected. Two more torpedoes hit the ship, which also caused a list. Another torpedo hit broke the vessel in two and she sank with all hands.

On 9 October, U-103 sank Zanes Gounaris and damaged Graigwen and Delphin. Delphin sank the next day. She sank Nora on 13 October and Thistlegarth, 45 nmi (83 km; 52 mi) west northwest of Rockall, on 15 October.

U-103 docked at her new base, Lorient on the French Atlantic coast, on 19 October.

U-103's second patrol began with her being unsuccessfully attacked by the Flower-class corvette HMS Rhododendron northwest of Ireland on 11 November 1940.

She then sank Daydawn and Victoria on 21 November, Glenmoor on the 27th, and Mount Athos and St. Elwyn on the 28th. The attacks continued with Calabria on 8 December and Empire Jaguar the next day.

The submarine returned to Lorient on 12 December.

On 13 February 1941 Arthur F. Corwin was damaged by U-103, and sunk by U-96 later that day. On 19 February U-103 sank the Norwegian motor ship Benjamin Franklin. The Flower-class corvette HMS Pimpernel rescued seven survivors, and landed them at Liverpool. The Egyptian steamship Memphis rescued 29 of her crew, but on 28 February Memphis suffered engine failure and sank with all hands.

U-103's fourth patrol was off the coast of West Africa. At 103 days, it was her longest patrol. She sank Polyana 41 nmi (76 km; 47 mi) southwest of the Cape Verde Islands on 24 April 1941. The ship sank with all hands in one minute.

U-103 sank Samsø, Wray Castle, Surat and Dunkwa in the first week of May. When Dunkwa sank, U-103's crew saw that there were 39 survivors in one lifeboat. The U-boat crew righted another boat and provided drinking water.

On 25 May, she sank the cargo ship Radames off the coast of Liberia. The sinking of the Radames was filmed, and is often shown on documentaries about the Battle of the Atlantic.

U-103 sank another seven ships off the African coast before returning to Lorient on 12 July.

U-103's fifth patrol was in the North Atlantic. It sank Niceto de Larrinaga, Edward Blyden and Lapwing west of the Canary Islands on 22 September 1941.

The U-boat's sixth patrol was part of Operation Drumbeat, off the Atlantic coast of the USA. She sank W. L. Stead about 90 nmi (170 km; 100 mi) off the Delaware River on 2 February 1942. The torpedo hit set the ship on fire but wave action soon extinguished it. Using her deck gun, U-103 fired 83 rounds, scoring 17 hits and reigniting the fire. She fired a further two torpedoes. The second missed, but the third detonated the tanker's cargo, sending flames 500 ft (150 m) into the air.

U-103 also sank San Gil on 4 February, and both India Arrow and China Arrow the next day.

U-103 began her seventh patrol by leaving Lorient on 15 April 1942. She sank Stanbank northeast of Bermuda on 5 May. She continued to the Caribbean and the Gulf of Mexico, where she sank another eight merchant ships that month. U-103 returned to Lorient on 22 June.

U-103 sank Tasmania north of Madeira on 31 October 1942, and Henry Stanley in mid-Atlantic northwest of the Azores on 6 December. She captured Henry Stanley's Master. He was eventually sent to the Milag Nord internment camp for merchant seamen.

U-103 also damaged Horata north of the Azores on 13 December.

On her ninth patrol U-103 sank no ships. She searched the Atlantic off Spain as far west as the Azores and as far south as Morocco, but found no convoys. Having left Lorient on 7 February 1943, she returned there on 26 March.

On U-103'S tenth patrol, on 27 April a Vickers Wellington of No. 172 Squadron RAF equipped with a Leigh Light attacked her. The aircraft found the U-boat with its radar, and dropped six depth charges, but caused no damage. A Whitley bomber of No. 10 OTU (Operational Training Unit) attacked U-103 on 22 May. U-103 returned fire, preventing the aircraft from dropping its depth charges. Plane and submarine both returned safely to their bases.

U-103's last operational patrol was officially divided into two parts; the first of which saw her arrive in Brest in France only two days after her departure from Lorient. She then returned to the west African coast but without repeating her earlier success. She sailed to Norway via a reverse in the course of her first patrol and arrived at Bergen on 1 January 1944.

U-103 took part in nine wolfpacks, namely:

• Störtebecker (5 – 7 November 1941)
• Streitaxt (29 October – 2 November 1942)
• Schlagetot (9 – 21 November 1942)
• Westwall (21 November – 16 December 1942)
• Robbe (16 February – 12 March 1943)
• Wohlgemut (12 – 19 March 1943)
• Amsel 4 (4 – 6 May 1943)
• Rhein (7 – 10 May 1943)
• Elbe 2 (10 – 14 May 1943)