Merchant Aircraft Carrier or MAC ship in convoy in 1943, photo taken from HMCS ARVIDA. MAC ships were merchant tankers converted with a flight deck, island super structure and could carry three to four aircraft on deck. These ships still carried material in their holds and therefore there were no interior hangars. The advantage was aircraft could be launched to fight off submarines and then recovered. Unlike the Catapult Aircraft Merchant (CAM) ships that, could launch a single aircraft to fight off a U-boat threat, then the pilot would have to ditch the plane and hope for rescue.

Roger Litwiller Collection, courtesy Howard Abbott, RCNVR. (RTL-HA062)