Nitrox is any mixture of nitrogen and oxygen. Plain old air, which is 21% oxygen and 79% nitrogen, is one example of nitrox. We've all been breathing nitrox all of our lives. Enriched Air Nitrox, or EAN, usually refers to mixtures that contain more oxygen than air does. Two flavors of nitrox that are very common are called EAN32 (which is 32% oxygen and 68% nitrogen) and EAN36 (which is 36% oxygen and 64% nitrogen).
It makes sense for divers to breathe more oxygen and less nitrogen since it's the nitrogen we breathe that can cause decompression illness. Extra nitrogen dissolves in our tissues when we're under water. If we get too much extra or we ascend too quickly, nitrogen bubbles can form. By breathing nitrox with less nitrogen, we reduce the excess nitrogen levels in our bodies. This results in longer bottom times (longer no-decompression limits) and/or increased safety margins.
It really does. For example, the no-decompression limit for a dive to a depth of 60 feet while breathing air is 55 minutes (check your dive tables). The no-decompression limit for a dive to a depth of 60 feet while breathing EAN36 is 115 minutes! That's more than double the bottom time! If you've spent time and money traveling to an exotic dive destination and can more than double your bottom time just by breathing the right gas, then it's worth the extra trouble. After all, bottom time is what we spent all the time and money for in the first place.
No. If you use a nitrox mixture than contains 40% oxygen or less, then no special equipment is necessary. If your equipment does come into contact with higher concentrations of oxygen, then it will need to be specially cleaned. (You will need to have access to an oxygen analyzer to check your nitrox mixture prior to every dive.)
The catch is that with extra benefit comes extra responsibility. Divers using nitrox have to be aware of extra safety precautions that divers using air usually don't have to worry about. As you remember from the open water scuba diver course, pure oxygen becomes toxic if breathed deeper than 20 feet. Every breathing mixture (even air) has a maximum safe depth. For example, EAN32 should not be used deeper than 110 feet.
Take a nitrox course. After a few hours in the classroom and two dives, you'll be certified to buy and use nitrox. You'll learn how to take advantage of all that nitrox has to offer as well as all the necessary safety precautions. Best of all, the two check-out dives can be combined with other courses you're interested in.
| Program: | Qualifies divers to use Nitrox... |
|---|---|
| EANx Diver | on no-decompression required dives within recreational limits using at most 40% O2 |
| Advanced EANx Diver | on dives as deep as 140 ft requiring no more than 15 minutes of decompression using EAN50 |