What is the approximate air supply duration at 130 fsw?

To determine the approximate air supply duration at a depth of 130 feet of sea water (fsw), it is important to understand the relationship between depth, pressure, and air consumption rates. At deeper depths, the pressure increases, which in turn affects the volume of air that a diver consumes.

At 130 fsw, the atmospheric pressure is approximately five times greater than at the surface (1 atmosphere of surface pressure plus 4 additional atmospheres due to the water column). This increased pressure leads to a higher air consumption rate, ultimately reducing the duration of available air supply.

Typically, divers can estimate air supply duration using a guideline that suggests you divide the surface air supply time by the ambient pressure in atmospheres. For example, if a diver has a supply that would last for about 50 minutes at the surface (1 atmosphere), at 130 fsw (5 atmospheres total), the available duration would decrease significantly.

In practical terms, 10 minutes is a commonly referenced duration for dives at 130 fsw when considering the increased rate of air consumption. This provides a benchmark for divers to prepare for their breathing gas needs and ensures they are aware of the limits of their air supply under higher pressure environments. Therefore, the most accurate answer