What is the definition of absolute pressure?

Absolute pressure is defined as the total pressure exerted on a diver or any object submerged in a fluid, which includes both the atmospheric pressure and the pressure exerted by the water above the object. This measurement is crucial in diving, as it determines the actual pressure experienced by a diver at any depth.

In water, the pressure increases with depth due to the weight of the water column above. At sea level, atmospheric pressure contributes a significant amount to the total pressure. Therefore, when considering absolute pressure, you must account for both the pressure from the atmosphere (air pressure) and the additional pressure from the water.

This definition emphasizes the importance of understanding how both components of pressure contribute to the overall pressure a diver experiences. It would not be appropriate to refer solely to the water pressure, the air pressure, or the pressure at sea level, as each of these alone does not encompass the combined effect that defines absolute pressure in the context of diving.