"Vindex" and "Nairana" were both commissioned within days of each other in December 1943, and moved to Gourock for working up. "Nairana" with 835 Naval Air Squadron Fleet Air Arm on board commenced flying exercises with HMS "Activity" on 27 January 1944. Both carriers left the River Clyde on 29 January with the 2nd Escort Group under the command of Captain Frederic John Walker. They were to form a "hunter killer group" in the waters west of Ireland, providing cover for two southbound convoys OS 66 and KMS 70. Weather conditions had prohibited flying until 31 January. With clearer weather "Nairana" turned into the wind to send off her first anti-submarine patrol. At the same time "Wild Goose" reported contact with a submerged U-boat on her ASDIC. Warning "Nairana" that she had just turned into danger, the carrier took avoiding action. The U-boat "U-592" was sunk by "Wild Goose" and Walker's own ship "Starling", while a Fairey Swordfish from "Nairana" circled the area.