Alternative term: Lightship
A vessel anchored at a designated geographical location as an aid to navigation, to mark a hazard or to serve as a landfall mark. It is equipped with a light of high luminous intensity and may carry a fog signal emitter, a racon, a radiobeacon or other aids to navigation as required by the particular station. It may or may not be self-propelled.
A light vessel serves also as a conspicuous navigation mark by day. For this reason the hull and the lantern support tower are usually coloured red. The name of the station is exhibited on either side of the vessel.
Please note that this is the term as it stands in the original IALA Dictionary edition (1970-1989)
International Association of Marine Aids to Navigation and Lighthouse Authorities - AISM