What is Nitrox? Nitrox, also known as enriched air EANx, is air with an increased percentage of oxygen. Normal air contains 21% oxygen and 79% nitrogen. By adding oxygen to the air the amount of nitrogen is reduced. At DJL we have a continuous flow Nitrox mixing system to produce Nitrox blends up to 36% oxygen and a partial pressure blending system to produce the richer Nitrox blends used in technical diving.
So why use Nitrox? The main benefit of Nitrox is longer dives as a result of increasing the no decompression limit. At shallow depths your dive time is normally limited by the amount of gas in your tank, but as you gain experience and qualifications and start making deeper dives you start to find yourself in the frustrating situation where you still have plenty of gas left in your tank but have to end the dive because you have reached the no decompression limit. Using Nitrox with the Nitrox version of the RDP or setting your dive computer to the correct Nitrox mix gives longer limits meaning longer dives. Many people also dive Nitrox for added conservatism. Using Nitrox with air tables or computers adds a degree of safety and many divers who use this technique swear they always feel better after a dive.
In technical diving Nitrox is used to reduce the time spent on decompression stops, typically using Nitrox halves the amount of decompression time required.
What training is available? Diving with Nitrox requires extra training. Although diving with Nitrox is generally considered safer than diving on air the increased oxygen in the mix means there are additional hazards that need to be considered. The primary risk is oxygen toxicity, at high pressures oxygen starts to become toxic meaning that all nitrox blends have a maximum operating depth. In the PADI enriched air diver speciality course you learn how to analyse your Nitrox and calculate your MOD. The Nitrox speciality course dovetails perfectly with the Padi deep diver and wreck diver speciality courses as Nitrox gives you the additional bottom time needed to explore wrecks at the depths they are typically found. All the courses are available through Davy Jones Locker diving here on Koh Tao.