What does the signal white over red mean in maritime navigation?

The signal white over red indicates that there is a pilot ahead, which is an important piece of information for vessels navigating in coastal or congested waters. Pilots are maritime professionals who are trained and licensed to navigate ships through dangerous or congested waters, and the presence of a pilot is crucial for ensuring safe passage.

When a vessel displays this signal, it informs other mariners that they should be aware and ready to assist if necessary, as the pilot may be boarding or departing the vessel. This signal enhances situational awareness among vessels in proximity and is vital for the safe management of traffic in busy maritime areas.

In contrast, the other signals are used for different specific purposes. The signal for fishing at night involves different light configurations, while warnings about shallow water are typically indicated by different colors or patterns. Lastly, a vessel in distress would signal using specific distress signals that are distinct from the indication of a pilot. Understanding these signals is essential for safe navigation and effective communication on the water.