What does red over red with an anchor light signify?

The combination of red over red with an anchor light indicates a vessel that is aground. This signal is important for the safety of navigation, as it alerts other mariners to the potential hazard posed by the vessel’s position. When a vessel is aground, it may be unable to maneuver, and other boats need to be cautious to avoid running aground themselves or colliding with the stranded vessel.

In this context, the red lights serve as a warning that the vessel is not in a position to navigate, reinforcing the need for other vessels to maintain a safe distance. Such signaling provides essential information to those in the vicinity about the vessel's status, contributing to overall maritime safety.