What does a white light that unexpectedly turns red indicate?

A white light that unexpectedly turns red serves as a critical warning signal indicating a potential hazard in the navigating area. In maritime buoyage systems, color coding is essential for informing mariners about what to expect in their navigational environment. When a vessel encounters a red light, it signifies danger or an obstruction, thereby alerting the mariner to take necessary precautions, such as altering their course or being prepared to navigate away from a potentially unsafe situation.

The use of red lights in this context is standardized to convey urgent messages, differentiating them from other light signals that may indicate safe passage, fair weather, or permissions for advancing through a channel. This established convention helps ensure that all vessels interpret light signals consistently, which is crucial for maintaining safety on the water.