It first flew on 23 August 1953, but, due to poor performance coupled with shifting defence doctrine, it never reached service and only 24 production aircraft had flown before the project was cancelled.

[6] The fourth Seamew prototype (XE175) was flown by Runciman for a series of sales tours in 1956 to Italy (March), Yugoslavia (April) and West Germany (May).

[N 1] The MR Mark 2 for use by Coastal Command was similar in every respect to the AS Mk 1 except that it was optimised for land-based use from hastily prepared airstrips.

Slightly heavier than the naval version, the MR Mk 2 had oversize low pressure tyres and could carry a higher weapons load.

The large, broad-chord wings featured power-folding and pylons for the carriage of rockets, depth charges, flares and small bombs.

The large, slab-like tailplane was mounted high on the vertical stabiliser, requiring the rudder to be split into upper and lower sections.

Arthur Pearcy wrote "only Short Brothers' test pilot Wally Runciman seemed able to outwit its vicious tendencies and exploit its latent manoeuvrability to the limit.

[12] An order was placed in February 1955 for 60 aircraft (split evenly between the FAA and RAF), with Seamew XA213 successfully completing carrier trials on HMS Bulwark in July and December 1955.

The RAF lost interest after four Mk 2s were built[9] with three of them converted to AS1 standard; the fourth (XE175) was flown by S/L W. "Wally" J. Runciman for a series of sales tours in 1956 to Italy (March), Yugoslavia (April) and West Germany (May).