Sector light

A sector light is a man-made pilotage and position fixing aid that consists of strictly delineated horizontal angle light beams to guide water-borne traffic through a safe channel at night in reasonable visibility.

The world has different navigation standards managed by IALA (International Association of Lighthouse Authorities).

The PEL sector light was constructed to guide US Navy vessels into the Diego Garcia port through a narrow entrance in the lagoon.

[4] The PEL sector light produces 3.5 million candela and is visible for 10 nautical miles (18.5 km) by day.

This has multiple white green and red sectors, indicating safe passage from several directions.

Sector light at Botveskär on the approach to Kapellskär , Sweden [ 1 ]
Example of a sector light. The ship is navigating in the safe sector (white light is commonly marked as yellow in nautical charts). [ 2 ]
The sector light of Kolnesholmane as shown on a 1970 nautical chart
The sector light of Flørauden as shown on OpenSeaMap