PADI Enriched Air Diver Course
Enriched Air or Nitrox is a breathing gas mixture that gives a diver a greater percentage of oxygen. Most divers use compressed air that has a mixture of about 21% oxygen, 70% nitrogen, and other trace gases.
Enriched air increases the amount of oxygen to allow for longer no-decompression limits.
Enriched air is not for deep diving. Special training and equipment is required.