page_title: Signal station
section_title: Current roles
hierarchical_section_title: Signal station / Current roles
caption_attribution_description: English: The tide signal station next to the Xingang Shiplock, at the North Taku Fort area of the Nanjiang Island of the Tianjin Port.
context_page_description: 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.
context_section_description: While radio has superseded the telegraph-relay role of signal stations, a number of signal stations remain in operation in situations where static visual signals provide fast access to specific safety information, such as traffic signalling in ports and narrow passages, or navigational warnings. In Japan, signal stations in the form of lighted letter boards are extensively used to mark traffic conditions, one way flows and predominant currents. Most ports elsewhere in the world will use a form of the International Port Traffic Signals system.
  Tide gauges are usually classified as signal stations, as they provide immediate visual information of tide levels.
caption: Tidal Signal Station at the Port of Tianjin, China
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