What does a green buoy signify?

A green buoy signifies that you are navigating in a specific channel or safe navigable waters, providing guidance to mariners. According to the IALA (International Association of Lighthouse Authorities) buoyage system used in the United States, green buoys are part of the lateral marking system. These buoys indicate that when returning to port or moving upstream, they should be kept on your left side. This helps to ensure that vessels remain within designated navigable channels and avoid hazards.

The other options relate to specific navigational purposes or activities but do not accurately describe the function of a green buoy in the lateral marking system. For instance, a marina entrance may be indicated by different signage and markers, while fishing zones and swimming restrictions are typically marked by other types of buoys or signs. Keeping this understanding is crucial for safe boating practices and effective navigation on waterways.