With "Vindex" damaged and needing a refit and "Campania" still not commissioned, "Nairana" was the only ship of her class fit for sea on 1 April 1944. She left in the first week of April with the outbound convoys OS 72 (West Africa) and KMS 46 (Gibraltar). She still had 825 Naval Air Squadron on board but this time she was overloaded with 18 aircraft: 12 Swordfish Mk IIs and six Sea Hurricanes IIcs. At the end of the month "Vindex" joined the 5th Escort Group. On 6 May a patrolling Swordfish was contacted by two of the escort frigates, who reported they were in contact with a submerged U-boat. The frigates carried out a depth charge attack and forced "U-765" to the surface. The Swordfish despite the anti-aircraft fire from the U-boat dropped two of its depth charges which broke the submarine in half.