Navigation light
lights on a vessel, aircraft or spacecraft giving information on a craft's position, heading, and status
A navigation light, also known as a running or position light, is a source of illumination on a watercraft, aircraft or spacecraft, meant to give information on the craft's position, heading, or status. Some navigation lights are colour-coded red and green to aid traffic control by identifying the craft's orientation. Their placement is mandated by international conventions or civil authorities such as the International Maritime Organization (IMO).
A common misconception is that marine or aircraft navigation lights indicate which of two approaching vessels has the "right of way" as in ground traffic; this is not precisely true, as aircraft and watercraft cannot stop to allow each other to pass, as ground vehicles do. However, the red and green colours do indicate which vessel has the duty to "give way" (change course or speed) or to "stand on" (hold course and speed). In a manner consistent with the ground traffic convention, the rightmost of the two vehicles is usually given stand-on status and the leftmost must give way. Therefore a red light is used on the port (left) side to indicate "you must give way"; and a green light on the starboard (right) side indicates "I will give way; you must stand on". When two power-driven vessels approach head-on, both are required to give way.
Marine navigation
In 1838 the United States passed an act requiring steamboats running between sunset and sunrise to carry one or more signal lights; colour, visibility and location were not specified.
In 1846 the United Kingdom passed the Steam Navigation Act 1846 (9 & 10 Vict.
“Navigation light” enters the record as lights on a vessel, aircraft or spacecraft giving information on a craft's position, heading, and status. Crown Archives preserves that source wording while asking what Navigation, light and lights can confirm, complicate or overturn.
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This entry incorporates text from “Navigation light” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.