Pilotage

Piloting (on water) or pilotage (in the air also British English) or land navigation is navigating, using fixed points of reference on the sea or on land, usually with reference to a nautical chart, aeronautical chart or topographic map, to obtain a fix of the position of the vessel, aircraft or land traveler with respect to a desired course or location. Horizontal fixes of position from known reference points may be obtained by sight or by radar. Vertical fixes of position may be obtained by depth sounder or by altimeter. Piloting is usually practiced close to shore or on inland waterways. Pilotage is practiced under visual meteorological conditions for flight. Divers use related techniques for underwater navigation.

Depending on whether one is navigating on a water course, in the air or on land, a different chart applies for the navigator:

Nautical chart – includes water depth.

Aeronautical chart – includes elevation.

Topographic map – emphasizes contours – suitable for land navigation.

Coastal mariners often use reference manuals, called "pilots" for navigating coastal waters. In addition to providing descriptions of shipping channels and coastal profiles, they discuss weather, currents and other topics of interest to mariners. Notable guides include a world-wide series of "Sailing Directions" by the United Kingdom Hydrographic Office (formerly by the British Admiralty) that includes, most notably, the English Channel, the Mediterranean Sea, the Red Sea and the Persian Gulf. Another series world-wide series of Sailing Directions is by the US National Geospatial-Intelligence Agency, which has planning guide and enroute portions. The "United States Coast Pilot", by the National Oceanic and Atmospheric Administration (NOAA) Office of Coast Survey, covers the coastal and intracoastal waters and the Great Lakes of the United States.

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