Which lights would be shown at night by a vessel which is restricted in her ability to deviate from her course?

A vessel that is restricted in its ability to deviate from its course is required to display specific lights to communicate its status to other vessels. According to the International Regulations for Preventing Collisions at Sea (COLREGs), this type of vessel exhibits three lights arranged in a vertical line: the highest and the lowest lights are red, and the middle light is white.

The use of two red lights indicates that the vessel is constrained by its draft or other restrictions, which prevent it from maneuvering safely. The white light, positioned between the two red lights, provides additional visibility and ensures that other vessels can recognize the situation. This specific configuration allows other mariners to understand that the vessel is limited in its ability to deviate from its course, which is critical for the safety and navigation of all vessels in the vicinity.

Understanding this lighting arrangement is essential for navigating safely and avoiding potential collisions in scenarios involving vessels with limitations on their movement.