At 00.31 hours on 26 Sep, 1941, U-203 fired a spread of four torpedoes at the convoy HG-73 north of the Azores and heard four detonations, but made no observations because they had to dive to evade an attack by HMS Larkspur (K 82) (Lt S.C.B. Hickman, RNR). Two ships were hit and sunk in this attack: Varangberg in station #52 and Avoceta, the ship of the convoy commodore in station #51.

The Avoceta (Master Harold Martin) was the ship of the convoy commodore Rear-Admiral K.E.L. Creighton, MVO, RN. The ship was hit on the port side close to the engine room by one torpedo and sank quickly. 43 crew members, four gunners and 76 passengers were lost. The master, the commodore, five naval staff members, 19 crew members, two gunners and 12 passengers were picked up by HMS Periwinkle (K 55) (LtCdr P.G. MacIver, RNR) and HMS Jasmine (K 23) (LtCdr C.D.B. Coventry, RNR (retired)) and landed at Milford Haven on 30 September. Three crew members were picked up by the Cervantes, which was sunk by U-201 (Schnee) the next night. The men survived the second sinking, were picked up by the British steam merchant Starling and landed at Liverpool on 1 October.