As an interim measure until more escort carriers could be made, selected British or Dominion merchant ships were fitted with an obsolescent Hawker Hurricane fighter to protect the ship (convoy) against air attack or reconnaisance overflights. The pilot was the only R.A.F. person on board, and had little to do unless the plane was needed. If an emergency arose, the aircraft would be catapulted off to do battle, then the pilot had to ditch and be fished out of the water. Though the planes could only be used once (they even had their landing gear deleted to save weight) they could save a grateful convoy from air attack.

In "Grand Fleet" the concept is taken further, and most navies equip their merchant ships with aircraft. Since surface raiders and submarines were an additional menace that fighters with machine guns alone could not hope to stop, attack aircraft sometimes were carried. Usually, obsolescent biplanes were used because of their greater lift at slow speeds. Rocket-assist could be used for heavy loads and one such Italian fighter-bomber put a big hole in HMS Rodney that was trying to interfere with the convoy carrying the Afrika Korps to Libya. Japanese C.A.M.'s disabled the French seaplane carrier Commandante Teste when she tried to interfere with the southbound invasion force at the war's outset. The C.A.M.'s greatest sucess came when a British convoy off East Africa sank the Vichy French aircraft carrier Joffre in Diego Suarez' harbor.