What is the primary function of a buoy?

The primary function of a buoy is to act as an aid to navigation. Buoys are floating markers placed in bodies of water to indicate specific locations or to provide information to mariners. They can mark safe channels, warn of hazards, guide vessels towards ports, and indicate navigational routes. The use of buoys helps to enhance safe navigation by providing visual cues to ships, which is critical for avoiding dangers such as shallow waters, rocks, or obstructions.

The other options do not accurately reflect the main purpose of a buoy. While a buoy can provide signals in distress situations, that is not its primary function. Similarly, it is not designed as a shelter for crew or as a storage facility for supplies, but rather serves a specific role in facilitating safe maritime travel.