Sea Slug was a first generation surface-to-air missile designed by Armstrong Whitworth (later part of the Hawker Siddeley group) for use by the Royal Navy. It came into operational service in the 1960s and was still in use at the time of the Falklands War. Sea Slug was intended to engage high-flying targets such as reconnaissance aircraft or bombers before they could launch stand-off weapons. Later improvements meant that it could also be used against ships.