What does a red sector light indicate?

A red sector light indicates danger areas. These lights are designed to warn mariners of perilous zones or obstructions that may pose hazards to navigation. When a vessel sees a red sector light, it serves as a crucial alert, signaling that the area ahead may be unsafe and the vessel should divert from that course. This is an important navigation tool, enabling safe passage by clearly marking where caution is necessary.

In terms of the other options, good water areas and safe turning points are generally indicated by lights of different colors that provide positive navigation signals. A marina entrance typically uses green or white sectors to indicate safe approaches rather than red, reinforcing that red is associated with caution or danger.