During World War I, the navies of the opposing forces discovered the value of aerial reconnaissance and many experiments were made to allow larger warships to carry one or sometimes two aircraft aboard. In the early days these were float planes that were lowered by crane into the sea and then lifted back aboard upon their return. This was a lengthy affair and when a speedy departure was necessary, time was of the essence. A new system was devised so that a powerful catapult system and a short ramp could, with the added speed of the ship, get an aircraft airborne in a fraction of the time previously required. Thus was born a highly specialised type of aircraft. This book includes all the major designs that went to war in the First and Second World Wars and includes aircraft used by all the combatants. It looks at how the aircraft evolved and how the warships were modified to accommodate the aircraft and the catapult system. The use of these fixed-wing aircraft was abandoned when the invention of the helicopter was made in the early post WW II years.