Supermarine Sea Lion II

When Venice hosted the 1920 Schneider Trophy between September 19 and 21, the Italians found themselves unopposed, and Luigi Bologna completed the 230.68-mile course in a Savoia S.12bis powered by a 500-hp Ansaldo V-12 engine, flying at an average speed of 105.97 mph. Venice was also the setting for the next race, on August 6 and 7, 1921 -- and again it was dominated by the Italians. France entered only one plane, whose takeoff was cancelled when its floats were damaged. The winner, Giovanni de Briganti, flew a Macchi M.7bis flying boat with a 280-hp Isotta-Fraschini V-6A engine through the 244.9-mile course at an average speed of 117.85 mph.

At that juncture, if Italy could win one more Schneider race, it would keep the silver trophy. The next event was held in Naples between August 10 and 12, 1922. France sent two flying boats. The Italians entered the Macchi M.17bis and a new biplane flying boat, the Savoia S.51. Britain fielded only one entry, the Supermarine Sea Lion II, also a biplane flying boat, powered by a 450-hp Napier Lion II engine. In the course of the race the S.51 crashed, killing its pilot. Adding to the Italians' setbacks was the narrow victory won by the Sea Lion, flown at an average speed of 145.72 mph by Henry C. Baird.

Design Company:

Supermarine Aviation Works Ltd

First Flight:


Sea Lion I:

1 - Supermarine (modified N.1B Baby)

Sea Lion II:

1 - Supermarine (modified Sea King II)

Sea Lion III:

1 - Supermarine (modified Sea Lion II)

Type Specification

Applies to:

Supermarine Sea Lion II


Single seat racing flying boat


Equal span two bay biplane


Wooden hull

Tail Unit:

Braced monoplane type mounted half way up the single fin with single rudder

Landing Gear:


Power Plant:

One 450 hp Napier Lion II engine mounted between the wings in pusher configuration


Single open cockpit for pilot only



32 ft


24 ft 9 in



Wing Area:

384 sq ft



2,115 lb


2,850 lb


Max Speed:

160 mph


3 hr