Navigation General · Aids to Navigation — Sector Lights
On many lighthouses, a red sector shown in the light's arc of visibility usually warns the mariner of:
- AA good anchorage
- BCalm water
- CA fuel dock
- DA hazard or foul ground within that bearing sector✓ Correct
Explanation
A red sector marks a danger area; if the mariner sees the light change to red, the vessel has entered the bearing arc covering shoals or other hazards and should alter to regain the white (safe) sector.
Authority: Light List; Chart No. 1
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