Signal station

A signal station is a form of Aids to Navigation that is defined by the IHO simply as "A signal station is a place on shore from which signals are made to ships at sea". 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.

History

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. As they were normally located in high places with extensive fields of view, surviving signal stations are often in scenic locations, and have become local landmarks.

Signal stations used a variety of means to communicate shore-to-ship: Chappe Telegraph or other forms of pole-and-arm optical telegraph,flag semaphore, heliograph, slat semaphore, and port-specific signals (like flag and ball weather warnings). The most widespread method was through different forms of flaghoist. Signals were often private signals, requiring local knowledge or code books.