The SeaCat fitting on the museum vessel taken 5 Sept 2011 at Chatham
Sea Cat was a British short-range surface to air missile system intended to replace the ubiquitous Bofors 40 mm gun aboard warships of all sizes. It was the world's first operational shipboard point-defence missile system and was designed so that the Bofors guns could be replaced with minimum modification to the recipient vessel using (originally) existing fire-control systems.
The initial system (GWS-20), and was intended to replace the twin 40 mm Bofors Mark V gun and its associated fire-control systems. The original director was based on the STD (Simple Tachymetric Director) and was entirely visual in operation. The target was acquired visually with the missile being guided, via a radio link, by the operator inputting commands on a joystick. Flares on the missile's tail fins aided identifying the missile. The more advanced CRBF (Close Range Blind Fire) director equipped with spin-scanning radar Type 262 for automatic target tracking could also be used.
GWS-20 was trialled on board the Daring class destroyer, and was subsequently removed. It was carried in active service by, (amongst others) Fearless class landing ships and Type 81 Tribal, updated Type 12 Whitby, Type 12I Rothesay and (originally) County class escorts. It was originally intended that all C class destroyers should receive it and the class were prepared accordingly. In the event only HMS Cavalier and HMS Caprice received it, in 1966 refits.