Aircraft diving in salute over the Royal Yacht. The salute; both military and naval; traces its origin to the act of displaying complete or temporary disarmament. In the Army this custom took the form of disclosing the open hand; and in the Navy to the discharging of the guns. The salute has now developed into a sign of greeting and respect; and in the Air Force takes the form of the aircraft diving towards the ground. At the Coronation Naval Review at Spithead on 20 May 1937; three flights of aircraft; representative of the Fleet Air Arm; flew above the Royal Yacht; and when overhead dived in a ceremonial salute to His Majesty. This episode is shown in our picture. Illustration for one of a set of 50 cigarette cards on the subject of Interesting Customs and Traditions of the Navy; Army and Airforce issued by Lambert & Butler in 1939.