Supermarine Seal II

The Supermarine Seal II was a British flying boat that Supermarine developed after winning an Air Ministry order for a prototype three-seater fleet spotter amphibian able to land on Royal Air Force aircraft carriers. R. J. Mitchell designed it, incorporating suggestions made after the Commercial Amphibian came second in the 1920 Air Ministry competition. It was a biplane with the lower wing mounted on top of the fuselage and a 450 horsepower Napier Lion water-cooled piston engine, and it was the first British flying boat with the propeller placed in front of the engine. The pilot sat forward in the nose with the fuel tanks behind him and a second cockpit behind the wing. It first flew on 21 May 1921 before assessment by the RAF, and after modification and a different engine it was renamed the Seagull. In November 1921 a Seal II was among the aircraft sold to the Imperial Japanese Navy Air Service and shipped out with the Sempill Mission.