Signal station

[1] While this broad definition would include coastal radio stations and fog signal stations, the term is most often used for shore installation that use visual signals to communicate with ships at sea.

Signal stations were the only practical mean of communicating with passing ships until the development of radio, and played a critical role in both navigation safety and commercial operation of fleets.

Signal stations used a variety of means to communicate shore-to-ship: Chappe Telegraph or other forms of pole-and-arm optical telegraph,[2] flag semaphore, heliograph, slat semaphore, and port-specific signals (like flag and ball weather warnings).

From the 1880s, Lloyd's operated a network of signal stations around the world,[4] connected to telegraph land-lines, that served to relay orders from owners and obtain reports from ships' masters.

In Japan, signal stations in the form of lighted letter boards are extensively used to mark traffic conditions, one way flows and predominant currents.