Leaving Northern Ireland on 9 March 1944, 2nd Escort Group moved to the area believed to hold the highest concentration of U-boats. Over the night of 12 March Swordfish on patrol had 28 contacts on their airborne to surface vessel radar (ASV). Their first attack was unsuccessful dropping two depth charges that failed to explode believed to be caused by faulty safety clips, during the attack the rear gunner in the Swordfish was killed by the U-boats anti-aircraft guns. The depth charges dropped short on a second attack and failed to explode on a third attack during the same night. On the night of 15 March two Swordfish got an ASV contact ahead of the escort group. Unable to see anything in the darkness they dropped flares and sea markers over the location. When the escort group arrived they picked up a contact on their ASDIC and the "U-653" was sunk.