What is the primary function of a buoyancy compensator?

The primary function of a buoyancy compensator is to help achieve neutral buoyancy. Neutral buoyancy is a state where the diver neither sinks nor floats, which is critical for safe and efficient diving. By adjusting the amount of air in the buoyancy compensator, a diver can control their buoyancy in the water column. This allows them to maintain a specific depth or to ascend and descend smoothly without expending unnecessary energy or putting themselves at risk.

When a diver wants to ascend, they can add buoyancy by inflating the compensator with air, making them more buoyant. Conversely, to descend or stay at a certain depth, they can release air from the compensator. This capability is essential for various diving tasks, including exploration, photography, and overall comfort while submerged.

Other options, like controlling underwater vehicle propulsion, regulating breathing gas supply, or providing warmth, do not pertain to the primary function of the buoyancy compensator. These functions are handled by other equipment or mechanisms in the diving system.