Not long ago, enriched air nitrox was something only cutting-edge technical divers used. Today, it’s widely used among recreational divers. Indeed, Enriched Air (Nitrox) Diver is the most popular PADI’s Specialty course.
Here’s what you need to know about earning an enriched air certification, the pros and cons of diving nitrox instead of air, and what this means for us as divers.
What is Nitrox?
Humans are accustomed to breathing air that’s approximately 79% nitrogen and 21% oxygen. Technically, any mixture of nitrogen and oxygen is nitrox – that includes the air you’re breathing right now.
In the recreational scuba realm, “nitrox” (also known as enriched air nitrox and EANx) typically describes breathing gas that is 32% or 36% oxygen. More oxygen means less nitrogen, and that has some nice benefits.
Can You Dive Longer With Nitrox?
As you learned in the PADI Open Water Diver course, nitrogen absorption is one of the things that limits our ability to explore underwater by determining how long we can stay at depth as well as how deep we can go. On the other hand, enriched air nitrox diving allows you to:
- Extend your bottom time (which might mean longer dive times)
- Shorten surface intervals
- Dive deeper on repetitive dives
Alternatively, many divers use enriched air to reduce the amount of nitrogen they absorb while sticking to the no-stop limits for air. This is a great way to be extra conservative during a dive and increase your personal safety margins.
Is Nitrox Worth It?
Even if you’re only making one dive, but it’s deeper than 15 meters/50 feet, there are some benefits you’ll gain from using enriched air.
- If you plan a dive to 21 meters/70 feet on air, your maximum no-stop time is 40 minutes.
- If you’re diving to the same depth with 32% enriched air, the no-stop time is 60 minutes—that’s a whole 20 minutes more of unfiltered underwater time (unless you use up the gas in your tank before then, of course).
Enriched Air and Repetitive Diving
Many divers wait too long to try enriched air. Indeed, many divers don’t realize the benefits of a nitrox certification until they’re already on their scuba vacation.
Imagine this scenario:
During the briefing, the Divemaster reminds the divers who are diving on regular air to mind their no-stop time. On the dive, you are forced to turn back before the enriched air divers. You watch with envy as those diving on nitrox swim the wreck, follow a stingray conga line, and discover sunken treasure.
All jokes aside, if you plan to do a multi-day dive trip or book that dream liveaboard, then do yourself a favor and get enriched air certified. Nitrox allows you to spend more time at depth compared to diving with air, which means you’ll get a lot more out of your scuba vacation.
What are the Pros and Cons of Diving With Enriched Air?
By now, you should have a good idea about why divers often choose nitrox over air. In summary, here are the advantages of nitrox:
- Longer bottom times and shorter surface intervals
- Dive deeper on repetitive dives
- Increased safety margins when diving within no-stop limits for air
- Many divers also say they feel less tired after diving with nitrox (although it’s not scientifically proven)
But if enriched air is so great, why doesn’t everyone dive with nitrox all the time? Good question. There are a few disadvantages of nitrox diving:
- Cost: Enriched air cylinder (commonly called a tank) fills typically cost more than regular air fills
- Depth limitations: To avoid oxygen toxicity, the maximum depth while breathing nitrox is shallower than air and depends on the blend (something you’ll learn during your nitrox certification)
- Availability: Not every dive shop or liveaboard offers enriched air
- Cylinder requirements: You need a dedicated nitrox cylinder for enriched air fills
Finally, bear in mind that using enriched air won’t change how much you breathe. This factor may still cut your dives short, so work on reducing your gas consumption to enjoy the greatest benefits of Nitrox diving.
A Few More Reasons to Get a PADI Enriched Air Certification
- Learn more about the features of your dive computer
- Improve your understanding of diving physiology, which is especially important if you plan to become a PADI Divemaster or Instructor one day
- You’ll need an EANx diving certification to enroll in technical diving courses
- Get one step closer to becoming a Master Scuba Diver
Start Your Nitrox Certification Online
Getting certified to use enriched air only takes a few hours. You can complete most of your nitrox training from home with PADI eLearning. A short, in-person session with a PADI Instructor where you’ll practice using an oxygen analyzer to check your gas mix (and a few other things) is all it takes to finish up. You’ll also have the chance to make two optional dives to put your skills into practice.
You may have heard that this specialty course is challenging, and you have to use multiple dive tables – not anymore. The PADI Enriched Air (Nitrox) Specialty course was updated several years ago. Now you use a dive computer for almost everything.