Normally a vessel without any means of self-propulsion, though in some countries they were, until recently, fitted with engines and moored over navigational hazards such a shoal or bank where, for whatever reason, it was impracticable to build a lighthouse. The lightship, like a lighthouse, displays a characteristic navigational light at night and a special mark by day, both easily identifiable and marked on charts. They are also equipped with fog signalling equipment and radar beacons, and come, like lighthouses, under the control of the national authorities like Trinity House and the Northern Lighthouse Board. In British and many other waters, they are always painted red and used to carry a crew of three or four, but nowadays they are all automated.
Subjects: Maritime History.