Supermarine Sea Lion II

Sea Lion II
Role Racing flying-boat
National origin UK
Manufacturer Supermarine Aviation Works
Designer R.J. Mitchell
First flight 1922
Number built 1
Variants Supermarine Sea Lion III

The Supermarine Sea Lion II was a British racing flying boat built by the Supermarine Aviation Works. Designed by Reginald Mitchell, the Sea Lion II was a modification of Supermarine's Sea King II. It was powered by a 450 hp (340 kW) Napier Lion engine.

Entered for the 1922 Schneider Trophy contest at Naples, Sea Lion II was planned to be able to attain a speed of 160 miles per hour (260 km/h). It competed against two Italian aircraft. Supermarine's test pilot Henry Biard flew the aircraft to victory at an average speed of 145.7 mph (234.5 km/h)—the first post-World War I success by a British aeroplane in an international competition.

The Sea Lion II was renamed the Sea Lion III for the 1923 contest, after Mitchell modified the design, and it was re-engined. .