At 03.36 hours on 14 October 1941, U-206 fired a spread of three torpedoes at HMS Fleur de Lys (K 122) (Lt A. Collins, RNR) about 55 miles west of Gibraltar. The corvette had escorted convoy OG-75 to port the day before and was ordered to patrol in the Straits of Gibraltar to search for U-boats that had chased convoy. One of the torpedoes struck her on port side under the bridge after a running time of 92 seconds, causing the magazine to explode. The ship broke in two and both parts disappeared within a few minutes. The commander, four officers and 65 ratings were lost. Only three ratings, two of them injured, survived the sinking and were picked up after a few hours by the Spanish motor merchant Castillo Villafranca.