The NAUI Nitrox Diver Program, usually consists of about three or four hours of academics during which a written exam is administered and some practical exercises involving calibrating gas analyzers and analyzing various breathing mixtures are conducted and your performance evaluated. After successfully completing the program your instructor will register you with NAUI Worldwide for an Enriched Air Nitrox certification card so that you will be able to have your dedicated EANx cylinders refilled with enriched air.
The NAUI Nitrox Diver Course includes the same academic and practical training components, but also includes at least two open water dives during which you will apply the knowledge acquired during the course. Completing the two required dives qualifies you to be registered for the Enriched Air Nitrox Diver certification card. In any event, either certification credential will provide you with the evidence you need to obtain enriched air wherever your diving adventures take you.