What is the primary use of a surface marker buoy?

The primary use of a surface marker buoy is to indicate a diver's position from the surface. When divers are underwater, it is essential for them to maintain a clear connection with their surface support team. Deploying a surface marker buoy serves this purpose effectively. It rises to the surface, providing a visible signal to boats, other divers, and surface personnel that indicates precisely where a diver is underwater. This is particularly important for safety, as it helps prevent accidents or people inadvertently coming too close to the diving area.

While signaling another diver's location and marking underwater hazards are important considerations in diving safety, they are not the primary function of a surface marker buoy. Similarly, providing ascent line guidance can be useful in certain contexts, but the buoy's main role is centered around its visibility from the surface for safety and communication purposes.