Many under-informed divers believe the myth that diving nitrox means that you can safely dive deeper. Nitrox has many benefits, but a deeper dive is not one of them.
What is Nitrox?
The difference between nitrox and normal air is the percentage of oxygen. Nitrox contains more than the 21% oxygen found in normal air but below 40% of the total. Nitrox tanks are filled with a mix of nitrogen and oxygen. Recreational divers typically dive a mix that is a 32% oxygen blend.
Blowing Up the Nitrox Deep-Dive Myth
Careless or inexperienced divers who don’t watch their depth or manage their buoyancy carefully can easily exceed the allowable depth of their dive, which puts them at a higher risk of oxygen toxicity (OXTOX). OXTOX is a greater hazard at deeper depths, and the higher oxygen percentage in nitrox blends means that there will be an increased risk of OXTOX as well as the risk of seizure and drowning.
Experienced divers are usually aware of the warning symptoms of OXTOX. While symptoms such as lights flashing before the eyes, ringing in the ears, nausea, fatigue, and confusion may warn of danger, they are not reliable since seizures can also hit without warning. Taking your dive deeper than tables allow is always a terrible idea, and that is all the more the case with nitrox.
The holy grail of SCUBA is finding a way to extend your bottom time, and this makes the use of nitrox appealing. When divers are breathing air at depth, the pressure from the water causes nitrogen from the air they are breathing to dissolve into the bloodstream. If you exceed your nitrogen load or neglect decompression stops as required, you put yourself at risk of Decompression Sickness (DCS), which means a painful trip to a decompression chamber or even death. Diving with nitrox minimizes nitrogen loading while increasing your bottom time.
Three Benefits of Diving Nitrox
Longer Bottom Time
Extending your dive time is a primary benefit of nitrox. The lower percentage of nitrogen in nitrox means that a diver experiences less nitrogen-loading during the dive. When you are taking on less nitrogen, your equivalent air depth (EAD) profile changes and you can dive longer. The dive time on a 30-meter dive can be doubled from 20 to 40 minutes, which is a significant improvement.
Shorter Surface Intervals
After investing precious time traveling to distant dive locations, maximizing your time in the water should be a priority. With multiple dives planned for one day, it is to your advantage to waste as little time as possible on the dive boat, off-gassing between dives. Nitrox limits your nitrogen-load and shortens your sit time, giving you more time underwater.
Many divers report that diving nitrox leaves them less fatigued following multiple dives. While this has not been proven scientifically, there is enough anecdotal evidence to suggest that older divers or less physically fit divers find that diving with nitrox helps relieve post-dive fatigue.
You will need to first become certified to dive nitrox so that you are not a danger to yourself or others. Once you’ve completed your certification, you will be able to responsibly and safely take to the water and catch those extra moments of solitude at depth.