What do alternating red and white lights indicate at night?

Alternating red and white lights at night signify a vessel in distress. This combination of lights is an internationally recognized signal indicating that a vessel is experiencing an emergency situation and requires assistance. The use of red can signify danger or emergency, while the white light serves to enhance visibility, making it easier to identify the distressed vessel.

The seriousness of distress signals is highlighted by maritime safety regulations, which state that vessels not only need to acknowledge such signals but also be prepared to assist if possible. Understanding this signal is crucial for all mariners, as a quick response can save lives and property when someone is in trouble at sea.

In contrast, the other options describe different scenarios that do not align with this specific light pattern. For instance, ships preparing to enter a port typically use navigation lights that do not alternate, and normal navigation lights adhere to specific configurations that do not include alternating colors. Celebratory events might involve specific signals, but these would not typically include alternating red and white lights, which could otherwise confuse other vessels regarding the actual state of distress.