nitrox diving

A “typical” nitrox sticker

Diving using nitrox

Nitrox diving has become increasingly popular in many parts of the world. Many qualified divers prefer to dive using nitrox for a number of reasons. In dive centers, dive sites and dive boats, it is difficult to miss the characteristic nitrox stickers found on scuba tanks.

There are a few common questions that people have when the prospect of nitrox scuba diving comes up for discussion. In this post we will try and answer to a few of the more common questions.

What is nitrox?

As many qualified divers might remember from their open water course, the air we breath roughly contains about 21% oxygen and 79% nitrogen. Nitrox can be defined as any mixture where the oxygen content goes above 21%. Generally speaking, when it comes to recreational diving, the oxygen content can be up to 40%. Other names used to describe this mixture are: Enriched Air, EANx etc.

Why use nitrox in scuba diving?

One reason why Nitrox is used in scuba diving in in order to reduce the percentage of nitrogen breathed. Breathing less nitrogen means that divers can extend their bottom time or no decompression limits. Less nitrogen in the breathing mix = less nitrogen absorbed.

For example, if diving to 18 metres:

  • with air (21% oxygen – 79% nitrogen)  your no decompression time will be 56 minutes;
  • with nitrox 32% (32% oxygen – 68% nitrogen), your no decompression time will be 74 minutes;
  • with nitrox 36% (36% oxygen – 64% nitrogen), your no decompression time will be 93 minutes.

Another reason is that nitrox diving allows for Shorter Surface Intervals. In plain words: since a diver will absorb less nitrogen for a given depth and dive time than by using air, there will then be less nitrogen to  “off-gas” during a surface interval. Less nitrogen to off-gas will mean a shorter surface interval.

Longer Repetitive Dive Times. If a diver wants to to maybe complete more than one dive in a day and extend time underwater, then nitrox diving is worth considering.

Reduced Exhaustion: It has been claimed that many divers have reported feeling less tired after diving on nitrox than after a similar dive on air.

So what are you waiting for? Have you considered doing a nitrox specialty?