Lanby buoy is a contraction of Large Automatic Navigation BuoY.[1] Lanby buoys were originally made by Hawker Siddeley Dynamics and were used from the 1970s onwards.[2] The buoys are intended to replace lightships and are constructed as a circular hull with a central light to provide all-round visibility and a foghorn. They may also contain radio and radio beacons.
The navigation buoy is monitored remotely from onshore and is designed to run for extended periods without repair. The running costs were estimated to be as little as 10% of those of a lightship.[2] A Lanby buoy replaced the Bar Lightship PLANET in the Mersey estuary in 1972 and remained in service for 21 years before being replaced itself.[3]