Nitrox is the term used to describe a specially enriched blend of oxygen and nitrogen used by professional and experienced scuba divers.
The usual accepted mix for Nitrox contains more than the regular 21% percentage of oxygen as is found in regular air, this can be anywhere from 22% of the mix up to the maximum of 40%. The most popular amounts for Nitrox mixes are 32% and 36%.
Also known as enriched air, this increased oxygen mix allows divers to extend the amount of time they spend at depth underwater (bottom time). Nitrox has been used by military dive teams the world over with much success, and they have produced many guidelines on its safe use by professional and recreational divers alike.
How Does the use of Nitrox effect my dives?
In the majority of dives it is the amount and rate at which the nitrogen is absorbed that dictates how much time can be spent underwater, the greater the absorption rate the greater the risk of the diver suffering from decompression sickness (in case of an emergency).
Using the increased oxygen mix, the risk of decompression sickness is reduced compared to using regular breathing air. This makes the Nitrox mix a good choice if a diver needs to extend his or her bottom time.
Reasons to Choose Nitrox
With the amount of oxygen in the air mix increased, the body will absorb less nitrogen, which means that a diver will need less decompression time in order to re-adjust the natural balance of oxygen and nitrogen in the body.
Less decompression time means that more time can be spent under the water. This extra dive time is extremely beneficial to people like marine biologists or professional underwater photographers. But in the end we all want more bottom time.
Some divers have also reported that using the enriched air leaves them feeling much less fatigued after a dive, presumably because of the increased oxygen supply to their muscles.
Do I need a specialty training to use Nitrox?
Yes you do. Specialist training courses are available that will educate and train divers in the safe use of enriched air, so that they have the option of its use available to them when they need to perform dives where extra bottom time is required.
The course covers the understanding and use of enriched air tables, enriched air compatible equipment, gear markings and tank filling. The enriched air which is used to fill the scuba tanks used for Nitrox must be properly analyzed using a Nitrox analyzer During the course you will learn how to do so.
Potential Reasons Not to Choose Nitrox
This oxygen rich air mixture is more expensive than regular air fills, and the use of it entails certain extra risk factors that need to be taken into account.
The use of Nitrox requires specific training and the use of specialized equipment which increases the time taken to prepare for a dive and the associated safety checks.
When using Nitrox a diver takes a greater chance of suffering oxygen toxicity than they would using the regular air mix, as a way of risk management a diver must take particular care to limit excessive exposure to pressured oxygen.
It is also of great importance to follow rigid time and depth limits in accordance with the percentage of oxygen being used in the Nitrox mix. All of these measures add extra time to the pre dive planning stages.
Whilst filling stations for regular air are easy to locate, it can be harder to find a Nitrox filling station. As in order to operate the staff need to have undergone specialist training and Nitrox handling procedures. If you are filling your tanks with enriched air, be sure to use filling stations that can verify that they have received and passed the training.
Blog written by: Rutger Thole who founded bookyourdive early 2012 because he saw that there was no simple and easy to use platform where divers could go to, to read scuba blogs, browse dive centers within locations and where they could read reviews from other scuba divers. Now working full time with a small dedicated team to ensure the best user experience a scuba diver gets on the web.