The design attracted the attention of the British Air Ministry, and two prototypes were ordered against Specification 12/21.
The watertight lower wings, mounted low on the hull where they were submerged when on the water, were intended to act as stabilising sponsons, eliminating the need for wing-tip floats.
[2] The hull was designed by Linton Hope who had designed the Kingston hulls, and accommodated the crew of four, with the pilot being provided with a cockpit amidships, positions for gunners in the aircraft's bow and in a dorsal location, while the observer was provided with an open cockpit just aft of the bow gunners position, and an enclosed position for operating the aircraft's radio inside the hull.
[6] Taxying at low speeds proved difficult, as the Ayr tended to rock from one wing to the other, although at speeds above 10 kn (12 mph; 19 km/h), the wings were lifted clear of the water by hydrodynamic forces, although keeping a straight course proved difficult.
The first prototype's hull was taken to RAE Farnborough along with that of one of the Kingstons, and was eventually abandoned on the Basingstoke Canal, sinking in the early 1950s.