What might a light on a lateral buoy indicate?

A light on a lateral buoy serves to indicate the direction of safe passage for vessels navigating through a waterway. In the IALA Maritime Buoyage System, lateral marks are designed to guide mariners along a channel by indicating which side of the buoy should be left to ensure a safe route. The color of the light, along with its characteristics, conveys critical information about the buoy's purpose and location in relation to the navigable channel. For instance, in the IALA Region A, green buoys typically indicate that a vessel should keep them on its starboard (right) side when entering a harbor or channel, while red buoys indicate the port (left) side.

This directional guidance is vital for safe navigation, helping to prevent groundings and collisions by clearly marking the safe route for vessels to follow. Therefore, understanding that lights on lateral buoys indicate the direction of safe passage is essential for effective maritime navigation.