The SR-N1 Hovercraft is supported on a cushion of air and operates at heights just sufficient to clear waves and surface irregularities on land. The lift principle of Hovercraft was discovered and developed by Mr C S. Cockerell, and in 1957 the Ministry of Supply sponsored a program of assessment and research carried out by Saunders-Roe Ltd. The SR-N1 Hovercraft is an experimental machine with space for the pilot and his observer, although on demonstration it has carried 20 fully equipped soldiers. It is powered by a 450 hp Alvis Leonides engine, giving a normal hovering height of 13 inches and maximum speed of about 25 knots. It weighs nearly 4 tons and is 30 feet long and 24 feet wide.

Markings for Saunders-Roe SR.N1, National Research Development Corporation (NRDC), English Channel, June 1959.