What distinguishes a distress signal by running lights?

A distress signal by running lights is characterized by flashing lights that deviate from standard navigation patterns. This flashing pattern is specifically designed to attract attention and indicate an emergency situation. When a vessel uses this method, the irregular timing and the brightness of the lights help differentiate the signal from regular navigation lights, which typically exhibit consistent characteristics and patterns. The intention behind this signaling method is to communicate the urgency of the situation to nearby vessels and prompt them to provide assistance.

Other options describe different phenomena that do not effectively communicate a distress signal. For instance, bright red lights that are always on may indicate a different condition or status, but they do not have the distinctive flashing component that signifies an emergency. One continuous color illuminating the vessel lacks the necessary urgency and variation required for a distress signal. Lastly, turning lights on and off periodically could suggest a malfunction rather than a clear distress signal, as it does not follow the specific conventions established for signaling distress at sea.