Between 23.10 and 23.12 hours on 7 May 1941, U-94 fired four torpedoes at the convoy OB-318 about 200 miles southwest of Reykjavik and reported four ships sunk, but Kuppisch apparently interpreted depth charges dropped by HMS Bulldog (H 91) (LtCdr A.J.B. Cresswell, RN) and HMS Rochester (L 50) immediately after the torpedoes had detonated on Ixion and Eastern Star as hits on other ships. The both escorts dropped together 67 depth charges on the U-boat, damaging it slightly.

The Ixion (Master Walter Francis Dark) was hit on the port side at hold #7 by one torpedo and sank. The master and 18 crew members were picked up by HMS Marigold (K 87) (Lt W.S. Macdonald, RNVR) and landed at Greenock. 77 crew members and nine gunners were picked up by the British merchant Nailsea Moor and landed at Sydney, Nova Scotia.