Sector lights

A leading light ( Maritime ) is a single- fire, which by sectors ( leading sectors, warning sectors ) of different identifiers a fairway, a harbor entrance or the open sea between shoals features.

To book a course identification used sectors with different colored light (eg green - white - red) or different timings ( blinking cycles ). The central sector is the leading sector and indicates the correct position. The two outer warning sectors indicate position deviations that require course corrections.