Searchwater was a maritime surveillance radar developed by Thorn EMI under project P1149. This type of radar has been in service with the Royal Air Force Hawker Siddeley Nimrod aboard the MR2 variant since the 1970s.[1]
The retirement of the Royal Navy's fleet carriers in 1978 meant that the airborne early warning (AEW) capable Fairey Gannet was also withdrawn from service. During the Falklands War, a number of warships were lost due to the lack of an indigenous AEW presence. Consequently, a greatly accelerated project was started to equip Westland Sea King helicopters with a slightly modified version of the system known as Searchwater LAST (Low Altitude Surveillance Task). The radome was mounted in a distinctive inverted cupola on a swivel arm attached to the right side of the fuselage just aft of the main door.[2] This arm allowed the helicopter to lower the radar below the fuselage in flight and to raise it for landing. Searchwater was retired from service when the last of the Royal Navy's airborne early warning Sea King helicopters were taken out of service in 2018.[3] The Searchwater system was subsequently replaced in the Royal Navy by the new Crowsnest system.[4]
Searchwater radar was developed by the Royal Signals and Radar Establishment and EMI (later Thorn Sensors Group). Racal Radar Defence Systems acquired Searchwater in 1995. Thorn and Racal merged to form Racal-Thorn Defence.[1]