At 05.07 hours on 13 Aug 1942, U-658 fired two spreads each of two G7e torpedoes while on the surface on the starboard quarter of convoy WAT-13 at a big tanker and a freighter of approx. 8000 grt and claimed both ships sunk after observing two columns of fire after 3 minutes 35 seconds and another after 3 minutes 58 seconds about 15 miles southwest of Cape Maysi in the Windward Passage. However, the Germans had misjudged the course and speed of convoy, so all torpedoes missed the intended targets and only one of them struck and sank Medea in station #74 while the British steam merchant Lodestone in station #43 was severely shaken by a torpedo that apparently detonated at the end of its run.

The Medea (Master Willem van der Heul) was struck by one torpedo on the starboard side aft in #3 hold. The explosion stopped the engines and caused several fires in the deck cargo which contained paint, benzine and chemicals. The 26 crew members and two gunners (the ship was armed with one 3in gun) immediately abandoned ship in lifeboats and on rafts without sending a distress signal while the Medea developed a heavy list to port and eventually capsized and sank about 5 minutes after being hit. Four crew members were lost. The master and 23 survivors were picked up after about one hour by the American submarine chaser USS SC-533, assisted by USS PC-478. They were transferred to HMS Havelock (H 88) (Cdr E.H. Thomas, DSC, RN) and landed at Guantanamo Bay later that day, where eight of them had to be hospitalized with injuries and one died of his wounds on 14 August.