What Is Nitrox Diving & Should I Get the Certification?
Candace Reno November 17th, 2025 Posted In: Articles Tags: SCUBA
SCUBA diving is an exhilarating sport that it feels like you just can’t get enough of. There’s been many times I’ve been diving and was not ready to surface. However, our limitations while diving underwater are there for our safety. We can expand some of those limits with nitrox diving.
Limitations of SCUBA Diving
The two biggest factors while SCUBA diving that limit how long you can stay under water are air consumption and no decompression limits.
- Air: Air consumption differs between different people. Some people don’t breathe much while others will always have relatively short dives due to breathing heavily. There are different size tanks that will also determine how long your air will last.
- No decompression limit: No decompression limit, also known as no deco time, bottom time, and no stop time, is the time you are allowed to be under water before a serious increased risk of decompression sickness. No decompression limits are based off of the old navy dive tables and adapted for recreational diving. The deeper you go, the less no decompression time you have.
What if there was a way to increase your no decompression limit while diving? Good news! That’s what we call nitrox diving!
What Is Nitrox Diving?
Nitrox, or enriched air, is a gas that has more oxygen than atmospheric air which is 21%. For recreational diving, that can range from 22-40% nitrox.
How Does Nitrox Work?
Nitrox works by reducing the amount of nitrogen you absorb while SCUBA diving. Since no decompression limits in SCUBA diving are based on nitrogen absorption, diving with air enriched with oxygen reduces the amount of nitrogen in your tank thereby reducing the amount of nitrogen you absorb.
Why Use Nitrox?
- Increased bottom time: Do you often find yourself diving between 60-100 feet? In my opinion, that is the best depth range to consider getting your nitrox certification. For example, when diving on regular air, your no decompression limit for your first dive of the day to 90 feet is only 25 minutes. When you dive with 32% nitrox, a standard blend, the no decompression limit changes to 35 minutes.
- Reduced surface intervals: Because you absorb less nitrogen while diving with nitrox, you don’t need as long of a time on the surface between dives.
- Feel better: You ever get done with a day of SCUBA diving and just feel exhausted? Besides the exercising, this is sometimes due to the nitrogen absorption. Nitrox makes you feel better after a day of diving. The increased oxygen you breathe in helps you feel better.
Limitations of Nitrox Diving
Maximum operating depth: Oxygen becomes toxic at depth due to the increased pressure. Thus, every blend of nitrox has limitations on maximum operating depth. The higher the blend percentage, the shallower your maximum operating depth is. If you go beyond your maximum operating depth for your nitrox blend, then you could have convulsions underwater which could lead to drowning.
Should I Get The Nitrox Certification?
If you find yourself diving below 60 feet and often feel like your time is too short underwater, you might consider getting your nitrox certification. It is important to get the certification for nitrox diving if you want to use nitrox. You can’t rent a nitrox tank or fill one without showing that you hold the nitrox certification. It is also dangerous to dive with nitrox if you don’t know what you’re doing.
The certification will show you how to analyze nitrox tanks to get an accurate reading of the blend which is very important to know you’re maximum operating depth to avoid oxygen toxicity.
Most nitrox classes now are offered as online learning. There is a portion of the class where you need to go to the dive shop to physically analyze the tanks. You don’t need to dive nitrox during the class to become certified in its use! Although, it would be recommended if it’s possible.
Almost every dive computer these days has a nitrox function making it easy to choose the right blend you are using for each dive. This means if you change tanks and have a different blend from your first dive, then you must go change that on your dive computer. This will allow your computer to automatically know your maximum operating depth and alert you if you get too deep.
Why Shouldn’t I Get The Nitrox Certification?
Not everyone should get or needs a nitrox certification. Those who would not benefit from nitrox diving:
- Divers diving less than 60 feet
- Divers diving more than 100 feet
- Divers who consume air rapidly
- Divers with medical reasons
Final Thoughts
Overall, nitrox SCUBA diving allows divers to increase their bottom time, reduce surface intervals, and feel better. Consider getting your nitrox certification today!
