Scuba Regulators and Considerations for Deeper Dives

When divers inhale through their scuba regulators, they are not breathing pure oxygen from scuba cylinders, as many people assume.

Scuba divers typically inhale compressed air -- which is 78 percent nitrogen and 21 percent oxygen.

In deep dives, the oxygen mix is higher to reduce the risk of decompression sickness and extend the dive time. Nitrox, which is usually referred to as Enriched Air (EAnx), is 64-68 percent nitrogen. It is effective in warding off decompression sickness up to 130 feet. Past that depth, a deep diving gas, such as Tri-Mix should be used.