I see the quizzical look on your face when I ask which Nitrox course you want to sign up for. Even after telling you the options your eyes ask if I’m crazy: “why on earth are there TWO different Nitrox courses?”
Well, I’m glad you asked, Jimothy!
Let’s start with the direct comparison of the Course Standards & Procedures for graduation requirements. In order to successfully pass this course the diver must:
SDI Computer Nitrox
- Students must achieve a minimum score of 80% on the Knowledge Quest or online final exam with 100% remediation.
- Analyze at least 2 nitrox cylinders and label cylinders in accordance with local practices and/or regulations
- Log at least 1 nitrox cylinder analysis to include: MOD and oxygen content
- Program a nitrox computer to a mix between 22-40 percent oxygen.
- Use TDI Tables to plan a nitrox dive taking advantage of EAD calculations.
- Create a simple written dive plan for a nitrox dive to a maximum operating depth (MOD) calculated with PO2 between 1.3 and 1.6 depending on environmental conditions.
- Demonstrate correct use of oxygen analyzer.
- Demonstrate correct cylinder management and labeling in accordance
with local practices and/or regulations.
- Conduct simple pre-dive briefing (may be simulated if dives are not part
- Program nitrox computer, if used, with appropriate oxygen percentage.
- Log at least 1 nitrox cylinder analysis to include: MOD and oxygen
Let’s cut to the chase…
Basically, the course difference comes down to math and tables.
The SDI course understands that the diver just wants to dive with the benefit of up to 40% EAN (Enriched Air Nitrogen), or Nitrox. They need to understand the dangers that come along with increased oxygen under pressure, be able to witness tank testing, log the appropriate mix, and update their computer. Easy-peasy!
TDI Nitrox, on the other hand, expects the diver not just to understand the math behind the MOD and EAD, but also to calculate it. And THEN you have to be able to use the US Navy Air Dive Tables to plot/plan your dive.
The understanding of the dangers and benefits of diving increased oxygen are the same in both courses. It’s being able to work out your EAD (equivalent air depth) and MOD (maximum operating depth) and plan a dive with pen and paper that really make the difference here.
But wait… there’s MORE!
If you upgrade within the next thirty minutes…
Just kidding. But still, while both courses get you to dive up to 40% O2, if you EVER think that you’ll POSSIBLY, every POTENTIALLY-MAYBE-NOT-SURE want to dive with more oxygen, like 41-100%, you’ll have to first take the TDI Nitrox course. Why? Because SDI doesn’t offer an “Advanced Nitrox” course.
In order to go north of 40% you have to cross over to, for lack of a better term, the dark-side of diving, and do it all over again with TDI!
The moral of the story…
At the end of the day, the course you choose doesn’t matter at all if you never want to advance your diving, or have zero desire to understand how the calculations behind the diving work. I feel this way about certain things as well… like crème brûlée. I want to eat it, but I have less than one fart to give about how it’s made or what’s in it because it might take it off the menu for me.
But if you aren’t sure about what you may or may not want to do with diving, or how deep and how long you might want to go underwater, then I’d recommend you take the TDI Nitrox. You get the same initial result with a bit more knowledge and abilities, and also a bonus of not being limited to advancing to the next level if you choose to do so
***kicks soapbox to the side***
See you under water!