At 05.59 hours on 30 Jun 1941 the Saint Anselm (Master Thomas Ross), a straggler from convoy SL-78, was hit by one torpedo from U-66 and sank by the stern after 25 minutes west of Madeira. The zigzagging ship had been spotted at 19.30 hours the day before and was missed by a first torpedo at 01.10 hours after which the master was alerted and avoided skillfully several attacks. The second torpedo fired at 01.46 hours from a distance of only 400 meters was avoided, also the next at 03.28 hours from 1000 meters. Two minutes later a torpedo hit but proved to be a dud while the fifth torpedo at 03.32 hours missed again. The U-boat then reloaded the tubes and fired another torpedo at 05.58 hours which was also a dud before the seventh torpedo hit one minute later.

34 men from the Saint Anselm were lost. The master and 17 survivors were picked up by HMS Moreton Bay (F 11) (Capt C.C. Bell (retired), RN) and landed at Freetown on 13 July. 15 other survivors were picked up by the Spanish steam merchant Tom and landed at Buenos Aires.