What does a green buoy signal in navigation?

In the context of navigation, a green buoy signals the left side of the channel when returning from the open sea or traveling upstream. This is part of the IALA (International Association of Marine Aids to Navigation and Lighthouse Authorities) buoyage system, which uses specific color codes and shapes to provide guidance to mariners.

When navigating towards shore, green buoys indicate the port side. This means that as you approach, the green buoy should be on your left side, ensuring that you're staying in the deeper, safe part of the navigation channel. Conversely, red buoys, which are typically on the right side, serve the opposite function. Understanding this system is crucial for safe navigation and helps prevent accidents and groundings. Knowing which side of the channel each buoy indicates helps boaters to orient themselves correctly as they move through waterways.