At 21.37 hours on 24 Dec 1943 the Dumana (Master Otto West) was hit on the starboard side in #2 and #3 holds by two of three torpedoes from U-515 while steaming on a non-evasive course at 8.5 knots in a very dark night about 70 miles west-southwest of Sassandra, Ivory Coast. The ship had been in convoy STL-8 but lost contact with the main convoy together with the armed trawlers HMS Arran (T 06) (Lt W.G.N. Aplin, RNR) and HMS Southern Pride (K 249) (Lt G.B. Angus, DSC, RNVR). Despite of warnings about U-boat activities in the area the torpedo nets of the vessel were not streamed and her escorts were unable to detect the U-boat which had even missed one of them with a Gnat torpedo fired at 21.18 hours.

The torpedo explosions blew away the starboard wing of the bridge, destroyed two of the starboard lifeboats and collapsed many of the wooden ladders to the troop decks, probably trapping some men in the mess decks. While the engines remained intact, the generators were apparently disabled as all lighting and communications immediately failed. The Dumana quickly began to list heavily to port, so the crew secured the engines and began to abandon ship. They launched #2, #6 and #8 lifeboats successfully but #5 was capsized by wreckage when reaching the water. However, the temporary houses on the shade decks broke adrift due to the list, slid overboard and fell onto the boats lying alongside, damaging the boats and killing some of the occupants. Other boats were dragged down with the ship when she sank by the bow in less than 7 minutes after being hit. Only the motorboat floated free and 40 survivors managed to climb into it. HMS Southern Pride screened the rescue operation of HMS Arran, which picked up the master and about 60 other survivors swimming in the water, leaving those who were safe in boats or on wreckage until the following morning. At daylight, both trawlers continued the rescue operation and picked up the remaining survivors, made a thorough search of the area until 11.30 hours and left for Takoradi, arriving in the evening on 26 December. The ship carried a crew of 36 Europeans and 103 Lascars, 21 RAF maintenance personnel and nine gunners (the ship was armed with one 4in, one 12pdr, four 20mm and four machine guns). 13 European crew members, 17 Lascars, two gunners and seven RAF personnel were lost.