A lightship, light ship or lightvessel is a vessel which is moored to serve as a navigational beacon, similar to a waterborne lighthouse or buoy. Today, LANBY and Texas Tower style markers have nearly entirely replaced lightships in operation.
The prominent design features are one or more large masts mounting the beacon apparatus, an increased anchor count, heavy mooring equipment, and a high-visibility paint schema which prominently displaying station name. Hull construction is typically robust, with prominent sheer and bow rise, rounded sterns, and often fair amounts of tumblehome. Decks tend to have relatively small deck houses, with the bulk of interior space used for accommodation and stores.