Nitrox diving, otherwise known as enriched air diving, is diving with a tank that has more than 21 percent oxygen. Usually scuba tanks use 21 percent oxygen and 79 percent nitrogen. The most common mixture is Nitrox 32 percent oxygen and 68 percent nitrogen.
Tanks with Nitrox or enriched air have clear markings with a green and yellow sticker. The maximum recreational limit for Nitrox is 40 percent oxygen. Any tank filled with Nitrox should be clearly marked with a green and yellow sticker. It also has a tag labelling the mixture and date it was filled.
What are the Benefits of Diving with Nitrox?
Safety
Diving with Nitrox indicates you’re diving with a higher oxygen content. At the end of the day, there’s less nitrogen in your body which reduces the chance of decompression sickness.
Extended Bottom Time
With the higher percentage of oxygen, divers are able to dive at depth for longer by reducing the amount of nitrogen that is absorbed by their bodies. Simply put, you can stay under for longer. It must be noted that the amount of air available in the tank is not different to a usual air tank. So a dive’s time will still be based on personal consumption.
Shorter Surface Intervals
Want to be able to get back in the water after a shorter surface interval? Enriched air means more dives per day. The diver absorbs less nitrogen at a given depth and time when compared with a normal air tank diver. The enriched air diver has to spend less time at the surface getting the nitrogen out of their bodies. Meaning they can get back in the water faster.
Longer Repetitive Dive Times
The Nitrox diver has less nitrogen in their bodies. If they do repetitive dives, they will have longer repetitive bottom dive times when compared with air.
Less Tired
You may feel less fatigued due to the increase in oxygen and reduced nitrogen level after a dive. Many divers report that they are less exhausted after a dive with Nitrox. This can be extremely helpful for those wanting to do more than one dive a day.
For those wanting to do a multi-dive day trip or a liveaboard. An enriched air (Nitrox) certification can be extremely useful. You’ll be able to dive at depth for longer, shorter surface intervals, and will be less tired.
Risks of Diving with Nitrox
Oxygen Toxicity and Depth Limits
To be clear, a gas containing any percentage of oxygen can cause oxygen toxicity when it’s at a high enough pressure. Oxygen toxicity is troublesome for divers because it can take place with little or no warning. The risk of Nitrox diving is that it can happen within recreational diving depths.
The two factors that contribute to oxygen toxicity are amount and length of exposure, also known as the oxygen limit. The exposure is calculated using partial pressures when the percentage of oxygen multiplied by the planned dive depth. The recreational scuba diving maximum partial pressure is 1.4 ATA. For Nitrox 36, 28 meters is the maximum dive depth. Thus, Nitrox is not suitable for deep dives. Plan each dive using tables or your computer, helping you keep to safe diving limits.
Nitrox Certification
To dive with Nitrox, get certified to learn about the benefits and risks, how to analyse a cylinder, maximum depth limits for different oxygen percentages, and how to use computers and tables to plan dives. As a certified Nitrox scuba diver, it is your responsibility to analyse the oxygen content of the tanks before diving.
Carrying your own oxygen analyzer may be a good investment. The percentage in the tank will be analysed by the diver before the dive. The maximum operating depth for this percentage will be calculated and will be used to plan the dive.
