The Supermarine Seagull was a amphibian biplane flying boat designed and produced by the British aircraft manufacturer Supermarine.
It was developed from the experimental Supermarine Seal II.
Development of the Seagull started during 1920, it heavily drew upon the prior Supermarine Commercial Amphibian program.
Flown for the first time on 2 June 1921, it was evaluated for military applications but was initially rejected, thus Supermarine continued development as a private venture.
During February 1922, a pilot order for two aircraft was placed by the Air Ministry, with follow up orders coming in shortly thereafter; production of the Seagull is believed to have been highly influential in Supermarine’s survival in an era typified by an industry wide drought of customers.
The Seagull was inducted into the Fleet Air Arm, where it was typically used for gunnery spotting and reconnaissance duties.
It was also operated by the Royal Australian Air Force for similar purposes, as well a single example being exported to Imperial Japan.
The Seagull’s assigned role in British service was that of a fleet spotter, being principally flown by 440 (Fleet Reconnaissance) Flight, operating from HMS Eagle.
During its service life, it determined to be most practically used for coastal reconnaissance missions.
The aircraft was normally operated by a crew of three (Pilot, Observer, and Radio-Operator), while the sole armament installed was a .303 in (7.7 mm) Lewis gun.
During 1925, the Seagull Mk II was the first British aircraft to conduct a catapult launch; the type was used extensively to test various designs of catapult, harnessing both cordite charges and compressed air to power them, prior to their widespread introduction.
That same year, the type started to be superseded by the Fairey IIId, as the practical value of the Seagull had been determined to be lacking in British service by this point.
The Australian Seagulls were operated by the No. 101 Flight RAAF; to avoid the need to build land facilities, they were typically based onboard RAN ships.
Even prior to the type’s delivery, the service had decided to perform a series of photographic survey flights, covering areas from the Great Barrier Reef to the Persian Gulf.
During its later life, the Seagull served on board HMAS Albatross, Australia’s first indigenously built warship.
Andrews and Morgan note that the Seagull appears to have been operated to greater success with the RAN than it was by the RAF.
Following an agreement made in 1922, a single Seagull Mk II was exported to Imperial Japan, intended to demonstrate and promote the capabilities of British aircraft and encourage further sales.