 Patrol number seven was in tonnage terms, the boat's most successful.Departing Brest on 27 June 1942, she operated in the eastern north Atlantic, sinking the Blue Star Liner east of São Miguel in the Azores on 6 July.Casualties were increased when a torpedo exploded under a lifeboat that had just been lowered from the ship and the remaining lifeboats became separated, one spending 20 days at sea before being rescued and another being lost without trace.