Fellow scuba enthusiasts, do you want your dives to be safer, to stay down longer, and to have more energy for celebratory drinks after rinsing out your gear? I’ll take that as a duh — which is why it’s so crazy it took me so many years to get my nitrox certification.
Earlier in 2016, before leaving Thailand for the summer, I realized I’d . My solution? I signed up for three different continuing education courses at three different dive schools on Koh Tao to shake myself out of it! And I chose topics that challenged me. After tackling the Self Reliant Diver certification at Master Divers — which you can read about here — I moved onto the Enriched Air Diver certification course at Ban’s, the largest dive school in the world by volume of divers certified.
The course, also often referred to as “nitrox,” is PADI’s most popular speciality — and it’s easy to see why. (I’ll use the two terms interchangeably throughout this post.) This simple one-day course can be done and dusted in a matter of hours, and in fact as a “dry course,” it can technically be completely without stepping a single fin underwater — though, ahem, why would you want to miss the fun part?!
I chose to take this certification quite seriously. As a PADI Divemaster, I have always felt self-conscious about the gaps in my understanding of dive theory, and I figured this course would be the perfect opportunity to fill them out. And so I turned to my longtime friend and Senior Instructor at Ban’s, Chris Pearson.
As the local coordinator at Hyperbaric Services Thailand, a key member of Koh Tao Rescue, and a PADI Staff Instructor, he was almost over-qualified to certify little ‘ol me in a simple Enriched Air course. I mean, just look at this list of qualification!
• PADI Staff Instructor
• Diver Medical Technician (IMCA)
• Emergency First Responder Instructor Trainer
• C.E.E.R – Challenging Environments Emergency Responder Instructor
• M.I.R.A – Medicine In Remote Areas Instructor
• DMR Level IV – Diver Medical Responder Instructor
• Hyperbaric Chamber Tender & Operator (SSS Recompression Chamber Network)
Phew! Thankfully, Chris was more than willing to take me on as a student. I knew he’d know exactly how to get the information through to me — Diet Coke lecture analogies, coconut quiz-passing bribes and all.
So, let’s start with the basics. What is enriched air? It all comes down to what’s in the tank. A standard scuba tank is filled with compressed air identical to what we breathe on land, which is 79% nitrogen and 21% oxygen. Nitrox tanks on the other hand have an oxygen content of 22-40%, with 32% and 36% being the standard mixes.
Don’t worry, this blog post does not require a calculator — I just wanted to impress you all with the use of fancy fractions. (Did it work? Discuss amongst yourselves.) Yet the real benefits of diving nitrox go beyond wowing your friends with math and the fashion potential of coordinating with those sassy green and yellow tanks.
Less nitrogen is, for the most part, a good thing. Nitrogen is enemy numero uno when it comes to decompression sickness, long breaks between dives, post-diving naps and something called “no decompression limits,” which calculate how long you can stay at certain depths. Diving enriched air allows you to dive longer (due to less nitrogen exposure), safer (you can dive an air profile on a nitrox tank for super conservative dives), with shorter surface intervals (as there’s less nitrogen to off-gas) and with less fatigue (yup, you guessed it, another byproduct of less nitrogen exposure).
So what keeps the entire dive community from ditching standard air and breathing nothing but nitrox? Good question. The answer, for most divers, is simply price. It’s more expensive! Other factors include limited availability, the hassle of checking the blend in your tank for each dive, and stricter depth limits due to the increased risk of oxygen toxicity (there’s always a trade-off, eh?).
The course itself is straightforward. In fact, it is the only PADI dive course ever to be streamlined rather than expanded. Why? Because, dive computers! In some ways, these magic little wrist machines have made diving nitrox as simple as the touch of a button.
But yet you still need to understand the concepts behind the calculations, and that’s where the certification comes in. Things like partial pressure and oxygen toxicity are, in my opinion, quite complicated, and I didn’t want to just pass the test and move on. I really wanted to understand. And so I didn’t move past a single sentence in the course manual until I felt confident I could explain it to a child if necessary. Bottom line? Praise Chris for his patience.
The course kicked off with an introductory video by PADI followed by a custom lecture from Chris and many interruptions by me to ask questions. Next, I sat down for some quality time with my manual, completing a simple knowledge reviews at the end of each chapter to seal in new concepts. Finally came the exam, which I aced with the humble pride that some accept PHDs with.
And then we put it into practice. After learning to set my dive computer for various nitrox blends, I mastered how to check tanks with an analyzer tool and record my findings, and finally how to read the markings on a nitrox tank. One thing I didn’t realize before taking this course is you MUST check your own gas blend each and every single dive so you can plan accordingly. While oxygen poisoning is incredibly rare, it is serious, and thus divers have to be vigilant about checking their air blend, making a dive plan and staying within their computer’s dive limits.
Ideally, though this step is technically optional, you’ll conclude your course with a dive or two on nitrox so you can see what all the fuss is about. Which is exactly what Chris and I did, to the HTMS Sattakut, one of my old favorite dive sites on Koh Tao.
While it was interesting to note the different readings on my dive computer and to see the different markings on my snazzy new tank, the contents were indiscernible otherwise from standard compressed air — it doesn’t taste, feel, or smell any differently.
Thanks to our longer dive time and shorter surface intervals, we were the last ones back on the boat from the first dive and the first ones back in the water for the second, at good ‘ol White Rock dive site.
And then I was certified, sealed with a high-five at the surface! As we hopped off the dive boat, I felt ready to take on the world — a far cry from my normal post-dive sluggishness.
So what divers should consider getting their Enriched Air certification? Anyone who wants to dive longer and feel sprightlier! Those doing multiple dives over multiple days — on liveaboards, at dive resorts, etc. — are the primary targets. Those looking to brush up on certain dive concepts (like me!) will also find it a great catch-all little course to really check your comprehension of dive theory, with the right instructor. And finally, those pursuing other specialities like Intro to Tech, Photography, Sidemount, and other courses that involve staying underwater for longer will find nitrox to be a natural step in their continuing education.
If you too are considering this course, you’ll walk away with a comprehensive understanding of what nitrox is, when and when not to dive it, what the risks are, and how to plan for enriched air dives.
I feel strongly that finding the right PADI dive shop and instructor are key when it comes to this course. I’ve heard it described by so many in the diving industry as “an easy sign off” and “a throwaway course” and while I don’t want anyone reading this to be discouraged or intimidated from signing up, I also don’t like to see it treated dismissively. So look for the right fit.
Only a handful of shops on Koh Tao compress their own enriched air. I recommend taking the course at a school that does, and asking your instructor if they actually use it. Ban’s is , and Chris is one of those instructors. Clearly, I was thrilled with my experience and can’t recommend Chris more highly. If you’re looking to take this or any other recreational diving or dive medic training course on Koh Tao,
Personally, I’ll be diving nitrox whenever it’s available and affordable to me from here forward. It just feels good!
And as someone who used to joke that I had to stop watching Bill Nye the Science Guy because all the theory was a bit over my head, I was proud to really wrap my mind around this course. If these things come easy to you, kudos! If not, don’t be discouraged. Science has never come easy to me, and for too long I let that mental block dictate what I thought I could and couldn’t achieve with diving. These days I know that with the right instructor, the right attitude, and a bribe of one fresh coconut for passing my final exams, there’s little in diving I can’t do.
Do you dive nitrox? Let’s get gassy in the comments!
This post is brought to you by PADI as part of the PADI AmbassaDiver initiative. Read on the PADI blog!