There is a common misconception about Enriched Air Nitrox that may cause some slight confusion. The statement that it allows you to dive deeper and longer than you can with normal air is not completely accurate. The difference between normal air and Nitrox is the higher percentage of oxygen. The oxygen percentage lies above 21% but under 40%. To provide some clarification we’ve got 5 facts about Nitrox and what advantages and disadvantages it gives you.
1) Longer bottom times! So this part of the rumor is actually true. Nitrox allows you to stay longer underwater than normal air. This is due to the smaller amount of nitrogen that you absorb. It is the simple equation: less nitrogen = longer bottom time.
2) This brings us to the second fact – shorter surface intervals. Of course, if you absorb less nitrogen your surface intervals shorten, because it takes less time to off gas on the surface. If you are planning to dive multiple dives over multiple days this is a big advantage.
3) Enriched Air also decreases the risk of decompression sickness. As said above, you are absorbing less nitrogen thanks to the higher oxygen content in your tank, and the risks are therefore decreased. For people who had DCS before or who maybe are not very fit, this is a great advantage. You can simply reduce the risks by doing the same dive profile but on Nitrox.
4) That being said you can’t dive deeper with Nitrox! Even if many people may think so. When breathing oxygen at high pressure it can become toxic so it tends to limit the maximum depth for the dive. So the higher the oxygen percentage the shallower the dive should be. You shouldn’t underestimate the risk of oxygen toxicity while diving with Enriched Air Nitrox.
5) Diving with Nitrox requires that you do the PADI enriched air diver specialty course first. In this course you are learning all about the theory of diving with Nitrox. For example: how to manage oxygen exposure, dive limits on Nitrox and what specific diving equipment you should consider. You can do this course in only about half a day and it doesn’t tend to be very expensive! If you are not yet PADI Advanced Open Water certified consider running it in Conjunction with your PADI advanced course as it’s a great opportunity to enhance your course!
So, Enriched Air Nitrox has advantages but these are not to be confused with common misconceptions!. It totally depends what kind of diving you are planning. We at DiveZENith are big fans of diving enriched air and are happy to incorporate the PADI enriched air diver specialty in to your experience with us, just ask!