Diving with Nitrox

Posted: Nov 14 in Dive Blog tagged Nitrox by Jan

Frustrated with short bottom times? Ready to stay down longer on your scuba dives? If you’ve been breathing regular compressed air, switching to Nitrox, which is an enriched air mixture, can help you stay down longer. Use of Nitrox has become increasingly popular among recreational, as well as technical divers.  Unlike recreational divers, technical divers may use several different enriched air mixtures during the course of their dives.

Regular air is a mixture of 78% nitrogen, 21% oxygen and 1% inert gases. When we dive, nitrogen from the air mixture is absorbed into our bloodstream and tissues. Too much nitrogen in our tissues can lead to decompression sickness, also known to scuba divers as “getting the bends.” When diving, we use our dive tables or dive computers to safely determine how long we can stay down without overloading our tissues with nitrogen. We may also need long surface intervals to allow enough nitrogen to leave our tissues before it is safe to dive again.

Enriched Air Nitrox refers to any gas mix with an oxygen content greater than 21%. Tech diving may also use the term “EANx”, where the “x” refers to the percentage of oxygen in the mix, such as EAN36. Within recreational diving, Nitrox blends are typically 32% oxygen or 36% oxygen. Technical divers with the proper training and certification,  may use additional Nitrox mixtures with 50% or even 100% oxygen during scheduled decompression stops.

While divers using a standard air mix worry about the bends, scuba divers using Enriched Air Nitrox blends need to be cautious of oxygen toxicity. Because of the increased percentage of oxygen used in Nitrox mixes, the oxygen in the mix may become toxic when breathed at increased depths due to the increased “partial  pressure” of the oxygen in the mix. For example, EAN36 is typically not used below a depth of 95 feet in order to avoid oxygen toxicity.

Divers  interested in using Nitrox must obtain additional training in the safe use and handling of enriched air gas mixtures.  Nitrox specialty courses are offered though numerous dive training agencies such as NAUI, PADI and SDI/TDI.   The certification course will teach you, among other things,  the benefits and potential hazards of enriched air diving,  how to use EAN dive tables and computers, the warning signs of oxygen toxicity, and how to get the most out of your scuba diving experience!  If interested, give us a call or check our calendar.  We offer Nitrox specialty classes on a regular basis.