Question

why is it important for a deep sea diver to ensure the pressure of the gas in the lungs is the same as the surrounding water in both ascent an descent ?

How does the diver accomplish this?

Answer 1

Hydrostatic pressure matters here. In the deep sea, the more water above diver and greater the weight of water. In this situation, the weight affects diver from all sides in same amount and incrases pressure per foot of seawater. At a depth about 10.1 m, the magnitude of hydrostatic pressure and atmospheric pressure is same.

At greater depths, the beating gas become heavier as its density increases. In this case, the diver should perform

greate efforts to breath. This limits the abiility of diver to ventilate the lungs adequately,