The outline of the Blue Water concept was unveiled in 1956: this tactical weapon was to be a large solid propellant rocket with inertial guidance ranging over 50 km. The missile with its launcher had to be transportable by air and land and have a quick launch reaction time. The prime contractor was English Electric, the GW Division of which had developed the Thunderbird SAM and was responsible of the Corporal in the British Army since 1956.
The resulting design was for a 1360 kg (3000-lb) rocket, 7.6 m (25-ft) long and
61 cm (2-ft) in diameter, with mid-section wings and large tail fins. Full development
started in 1958 and proceeded rapidly with preliminary test vehicle launches at Aberporth
and Woomera. Thirteen 3/8 scale flight models were fired at Woomera between late 1958
and early 1959 to determine the aerodynamic behavior.
The Blue Water propulsion requirement was initially answered by an IMI Summerfield motor called Saluki. Saluki contained a dual grain charge (560 + 442 kg of CDB propellant) which delivered 195.5 kN for 6 s and 35.6 kN until 27 s. The first static firing with a full scale propellant charge was carried out in October 1958. This was followed in April 1959 by the first static firing of a lightweight - strip laminate case - motor. The first Blue Water flight occurred on 21st April 1960 from Aberporth using a heavyweight motor and the first flight using the lightweight motor case was on 26th April 1960. Over the next two years, the flight tests series progressed as far as the 15th flight (on 7th June 1962) and the 5th launcher proving trial (on 16th July 1962). Then, following ministerial changes in London, Blue Water was suddenly cancelled on 10th August 1962.
The operational version was to be equipped with a dual chamber motor (boost and sustainer) allowing selective ignition time for the sustainer and thus better targeting flexibility. A polyurethane propellant motor proposed by Westcott was selected. This new motor called Phoenix, incorporating a petal valve between the two propellant charges contained in separate chambers, was to deliver 9,000 kN for 10 s and 1,350 kN until 27.5 s. At the time of Blue Water cancellation, development of Phoenix had reached the stage of 17-in test motors static firing. Tests continued on a research basis and a 24-in dual chamber motor was successfully statically fired in November 1964.