What is the primary purpose of the navigation lights on a vessel?

The primary purpose of navigation lights on a vessel is to signal other vessels about direction and position. These lights allow boaters to identify the type, size, and direction of travel of other vessels during nighttime or low visibility conditions. Each light has specific meanings; for example, a red light indicates the port (left) side of the vessel, while a green light indicates the starboard (right) side. Additionally, a white light typically indicates the stern (back) of the vessel. This system of navigation lights is crucial for maintaining safety on the water, as it helps prevent collisions by providing essential information about the presence and movement of other boats.

While other options may seem relevant at first glance, they do not accurately reflect the functional purpose of navigation lights. Speed indication pertains to devices like speedometers, aesthetic appeal is a secondary consideration in vessel design, and marking docking points is typically done with other navigational aids, not lights.