Supermarine S6 seaplane, c 1931.

Watercolour painting by Stanley Orton Bradshaw, showing the aeroplane that won the 1931 Schneider Trophy. Designed by Reginald Mitchell and made by Vickers Ltd, the S6 was powered by a Rolls Royce 'R' engine, and won the Schneider Trophy with a speed of 328 mph (528 kmh). The S6 led to the development of Mitchell's famed WWII fighter, the 'Spitfire'. The Schneider Trophy was awarded to the fastest and most seaworthy seaplane from 1913 to 1931, and in 1931 was awarded to Britain outright following a third victory. Two weeks after the Schneider Trophy the aeroplane became the fastest vehicle on earth, setting an absolute speed record of 407.5 mph.