Sector Light

A navigational light that shows different colours or characteristics in defined directions or is visible only within a specified sector.

Sector boundaries can mark a channel, danger, turning point or approach line. A common arrangement shows white in a preferred sector and red or green towards hazards, but colours and their meanings must be taken from the chart and light list rather than assumed. Transitions may be indistinct because of lens design, atmospheric conditions, observer position and chart uncertainty. The light’s bearing, elevation, range, obscured arcs and boundary bearings should be used with other navigation information, not as a single precision boundary.