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Technical Diving


Tech Diving

Technical Diving

LogoCave DivingTech Diving - What is Nitrox

Nitrox is any combination of nitrogen and oxygen. You have been breathing nitrox since the day you were born. The air that we breathe is comprised of approximately 21% oxygen and 79% nitrogen.

Nitrox mixtures with percentages of oxygen greater than 21% are called Enriched Air Nitrox (EANx). The commonly used EANx mixtures are EAN32 (32% oxygen / 68% nitrogen) and EAN36 (36% oxygen / 64% nitrogen). Special user friendly decompression tables for these EANx mixtures are available in waterproof format.

Who uses EANx?

EANx was first used in 1912 and has been used extensively for over thirty (30) years by commercial organizations and the military. It has also been used in the medical field as a therapy gas. Advanced level divers have been taking advantage of EANx for cave diving, wreck diving, marine harvest and many other diving applications. More recently, EANx has been recognized by international Scuba Diving certification agencies as an alternate breathing gas for recreational diving.

Isn't it for deep diving?

Many divers mistakenly believe EANx is used only on deep dives. Actually, the ideal range of EANx is between 12 meters and 40 meters, the standard recreational depths.

EquipmentWhat about oxygen toxicity?

As a certified air diver, you were taught how to monitor your nitrogen uptake by utilizing a set of dive tables. The deeper the depth, the shorter the amount of allowable no-decompression bottom time available due to nitrogen accumulation. The same principle applies to oxygen at deeper depths. The greater the depth, the shorter the bottom time. Oxygen toxicity (on air or nitrox) usually comes into play deeper than at the standard recreational depths of 12 meters - 40 meters. EANx dive tables provide a reliable, conservative and easy way to dive between 12 meters - 40 meters, while taking advantage of EANx benefits.

What are the benefits of EANx?

EANx diving has many advantages over air diving. Some of the benefits are:

  • EANx, when used with standard dive tables or computers, provides a tremendous safety factor. In fact, when utilized in this fashion, the actual nitrogen accumulation is that for a 3 to 6 meter shallower dive. This application of EANx is actually ideal for divers who simply wish to be more conservative, those individuals who are not as young as they once were or those who may not be in the peak of physical fitness

  • A significant increase in bottom time no-decompression limits

  • A reduction of the possibility of decompression sickness

  • A slight reduction in nitrogen narcosis

  • A reduction of decompression time if the no-decompression limits are exceeded

  • Reduced fatigue after the dive (declared by many EANx divers)

I have read that Nitrox is risky. Is this true?

Some of those who question the use of EANx lack the certification and complete knowledge to competently write and report on Nitrox's recreational use. With proper training, the risks of EANx diving are similar to air diving. Both have strict depth and time limitations. The treatment of Decompression Sickness (DCS) in recompression chambers is also similar with both EANx and air.

Nitrox Diving and Asian Adventures

If you're a nitrox qualified diver and you want to get the most out of your diving while you're in Phuket, then look us up when you get here. Our daytrip vessel has 14 nitrox tanks on board. We do onboard fills for US$ 3 per tank. Our two standard mixes are EAN32 and EAN36. These two mixes are perfect for the depths in the local dive area, which range between 24 meters/80 feet - 30 meters/100 feet. If you're interested in becoming certified to dive on nitrox then take a look at our pages on nitrox courses. You have a choice of the IANTD basic nitrox course or the PADI nitrox specialty certification.

A comparison of NDL's for AIR, EAN32 and EAN36



51 min

75 min

75 min


25 min

35 min

51 min


14 min

20 min

20 min

Maximum Po2 used = 1.6 ATA for EAN36
Tables used = Buehlman zhl - 16 Algorithm


The Low Down




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