[2] The Dolphin was a two-bay, single-seat biplane, with the upper wings attached to an open steel cabane frame above the cockpit.

This configuration sometimes caused difficulty for novices, who found it difficult to keep the aircraft pointed at the horizon because the nose was not visible from the cockpit.

[3] A pair of single-panel shutters, one in front of each radiator core and operated by the pilot, allowed the engine temperature to be controlled.

The first Dolphin prototype was powered by a geared 150 hp (110 kW) Hispano-Suiza 8B-series V-8 engine and featured a deep "car-type" frontal radiator.

On 13 June, the prototype flew to Saint-Omer, France, where the aircraft's unfamiliar shape prompted Allied anti-aircraft gunners to fire on it.

[8][11] The third and fourth prototypes incorporated numerous modifications to the radiator, upper fuselage decking, fin and rudder.

The Dolphin's debut was marred by several incidents in which British and Belgian pilots attacked the new aircraft, mistaking it for a German type.

New pilots also voiced concern over the Dolphin's wing arrangement, fearing serious injury to the head and neck in the event of a crash.

[14] Early aircraft were often fitted with improvised crash pylons consisting of steel tubes over the cockpit to protect the pilot's head.

Night-flying Dolphins of 141 Squadron, a Home Defence unit, had metal loops fitted above the inner set of interplane struts.

The Dolphin was often sent against German reconnaissance aircraft such as the Rumpler C.VII, which in its specialized Rubild photo-reconnaissance version, routinely operated at altitudes above 20,000 ft (6,100 m).

[18] In October 1918, the American Expeditionary Force purchased five standard Mk Is for evaluation, sending four back to the United States.

[27] Limited production capacity for the geared Hispano-Suiza HS.8B engine and the priority afforded to French aircraft like the SPAD S.XIII slowed Dolphin deliveries.

Availability of the Hispano-Suiza improved in early 1918 as the French firm Emile Mayen began deliveries on an order placed by the British Admiralty.

The French firm SACA (Société Anonyme des Constructions Aéronautiques) commenced licensed production of the Dolphin Mk II in 1918.

The RAF expressed no interest in this variant, which was intended for the French Aéronautique Militaire and the US Army Air Service.

[36][37] The Mk II's 300 hp (220 kW) direct-drive Hispano-Suiza 8F gave a maximum speed of 140 mph (225 km/h) and a ceiling of 26,401 ft (8,047 m).

[19] The Mk II also featured an additional fuel tank, a variable incidence tailplane, strengthened airframe and longer exhaust pipes.

Persistent difficulties with the geared 200 hp (150 kW) Hispano-Suiza 8B prompted development of the Dolphin Mk III, which used a de-geared version of the engine.

[3] Many Dolphins were converted to Mk III standard at aircraft repair depots by removing the reduction gear from the engine and fitting a revised cowling to accommodate the lower thrust line.

In March 2012, the Dolphin was placed on display at the Royal Air Force Museum London in the Grahame White Hangar.

[38] In 1977, Cole Palen built an accurate Dolphin reproduction for his Old Rhinebeck Aerodrome living aviation museum, in the mid-Hudson Valley of eastern New York.

It flew regularly at Old Rhinebeck's weekend air shows until September 1990, when it crash-landed after a fuel pump failure.