How Boyle's Law Applies To A Diver's Clothes and Equipment
When a diver descends, air pressure is increasing, but its volume is decreasing. The air becomes more and more compressed. This affects the air pockets in clothing, so that the wet suit feels tighter. This effect is known as skin squeeze, and may cause physical trauma. The diver has to compensate for the lost volume by releasing air into the inflatable vest or jacket known as a Buoyancy Compensation Device (BCD).
In the descent, all of the air pockets in the diver's body are also affected by this compression, including that in the sinuses, teeth, ear canals, mask, and even the airspace behind the ears. Divers compensate by exhaling into the mask. Conversely, as the diver ascends, he or she must get rid of the excess air by releasing it from the BCD vest. TheScubaGuide.com gives a basic tutorial on air pressure, with a chart on how it, the volume, and the air density changes at varying sea levels. Equipment that is designed for a diver's use must take into consideration how all of these changing conditions may affect him or her.
Navy Diver from NavyDivingCommunity.com