Clearing Puget Sound 6 February 1943, Core qualified pilots in carrier operations off San Diego, then sailed on to the east coast, arriving at Norfolk 11 April.

She continued to train pilots in Chesapeake Bay until 27 June when she sortied as the nucleus of TG 21.12,[1] a hunter-killer group.

Such groups, providing cover for the movement of convoys, made a contribution of great significance to winning the Battle of the Atlantic, and the innovation represented by their formation was a marked advance in antisubmarine warfare.

Planes from Core worked in coordination with accompanying destroyers scoring a number of successful attacks.

From 3 April to 29 May, she operated with TG 21.16 in the central and North Atlantic, then sailed from New York 24 June to ferry 85 Army aircraft to Glasgow, Scotland, returning to Norfolk 20 July.