A Sea Hurricane mounted on a catapult in the bows of a merchant ship. Image copyright Imperial War Museum reference IWM A9419
From the summer of 1941, Britain converted 35 cargo ships into 'Catapult Aircraft Merchantmen' (CAM ships). These were able to launch a Hurricane fighter aircraft from a rocket propelled trolley catapult. The Hurricanes were usually manned by RAF pilots from the Merchant Ship Fighter Unit, based at RAF Speke in Liverpool.
Unfortunately these ships had no flight decks on which the planes could land. Each fighter had to be ditched into the sea after just one mission. Although they rarely launched their planes, these ships were a useful deterrent against enemy aircraft on Atlantic, Gibraltar and Arctic routes.