On today’s dive boats, you’d be hard-pressed not to see one or two of the telltale green and yellow tanks that announce the presence of nitrox, or oxygen-enriched air, which has been used in recreational diving for decades. Every major training agency has a nitrox training program in one form or another. But is it right for you? As with anything in diving, there are no absolutes when diving nitrox. We’ll explore what nitrox is and what its practical uses are for the everyday diver.
What is it?
Nitrox is a term used for the mixture of nitrogen and oxygen. Recreational scuba divers use a blend of Nitrox that is usually a mixture of 21- 40% oxygen and 60-79% nitrogen. Often the terms “nitrox” and “enriched air” are sometimes used interchangeably, however they are not the same. “Nitrox” refers to any mixture of nitrogen and oxygen, while “enriched air” refers to mixtures of oxygen and nitrogen that contain more than 21% oxygen.
When you dive, the water pressure causes nitrogen from the air you’re breathing to dissolve in your bloodstream. The higher the pressure, the more nitrogen will dissolve. After a certain concentration of nitrogen builds up, you must come back to the surface slowly in order to avoid either mandatory decompression stops or a case of decompression sickness (DCS).
What Are The Benefits?
Longer Bottom Times
The reduced percentage of nitrogen in recreational Nitrox allows divers to extend their no decompression limits or dive time by reducing the amount of nitrogen absorbed. This means the less nitrogen there is in a diver’s breathing gas, the slower their nitrogen absorption will be at a given depth.
Shorter Surface Intervals
A diver who uses nitrox absorbs less nitrogen for a given depth and dive time than a diver using air. This means that the nitrox diver does not have as much nitrogen to “off-gas” during a surface interval, which can shorten the required surface interval significantly.
Longer Repetitive Dive Times
Nitrox becomes especially useful for divers who complete more than one dive per day and is most commonly used on live-aboard adventures where it is common to do multiple dives per day. A diver using Nitrox will have a longer allowable bottom time on a repetitive dive than a diver using air because the diver using nitrox has absorbed less nitrogen.
Many divers claim to feel less tired after a dive on nitrox than after a similar dive on air. By reducing a diver’s nitrogen absorption, nitrox may also reduce a diver’s post-dive exhaustion.
Really, this gas is just like everything else in a diver’s bag of gear and knowledge—
a tool that can be effective when used properly and dangerous when not. You will need specialized training to use nitrox and Ski/Scuba Center Inc of Knoxville can provide that training for you with their Nitrox course.