What does the term "buoyage" refer to?

The term "buoyage" specifically refers to the system of marking navigation hazards and channels. This system employs a variety of buoys and markers to help sailors safely navigate through waterways by clearly indicating safe routes, hazardous areas, and other critical navigation information.

This system is vital for the efficiency and safety of maritime navigation as it provides visual guidance to vessels, indicating whether they should navigate to the right or left of a buoy, which is colored and shaped according to internationally recognized standards.

In contrast to the other options, which focus on aspects not directly related to the function of buoys in navigation, "buoyage" emphasizes the entirety of the marking system necessary for safe navigation in maritime environments. The construction and maintenance of buoys, while important, are not encompassed by the term "buoyage" itself.