Aircraft operating from escort carriers like HMS Trumpeter, seen here in St. John's Harbour in late 1943 or early 1944, were essential to countering the threat from German submarines (U-Boats).

These small aircraft carriers could accompany convoys to provide air cover, with their aircraft searching for and attacking German submarines. Escort carriers could also form the core of hunter-killer or support groups, working with anti-submarine ships like frigates and destroyers to hunt down U-Boats or to help defend threatened convoys.

George Metcalf Archival Collection
CWM 20030014-057_7