What does the signal of red over white indicate when at sea?

The signal of red over white when at sea signifies that a vessel is engaged in fishing activity at night. This color combination serves as a warning to other mariners that the vessel may be limited in its ability to maneuver due to fishing gear or activities. The presence of the red light indicates that the vessel is actively fishing, while the white light acts as a secondary light to enhance visibility for other ships in the vicinity.

Understanding the importance of this signaling is crucial for maritime navigation safety. By correctly interpreting the red over white signal, other vessels can take necessary precautions, either by altering their course or by being vigilant when passing near the fishing vessel, thereby minimizing the risk of collision or interference with fishing operations.