PADI not teaching theory re/EANx

[TMHeimer]

I rarely have used Nitrox. Took the course in '06 when tables were the norm and 2 dives were required. I still review a problem with the tables every other day (the ones from the course that I kept). Have no idea why. I am not a geek either. OCD I guess.
When I did the Deep course ('07) I had the same instructor that I had for Nitrox. Our depth was to 130', so he told me to use the formulas to determine gas mix (it was to be 28). I don't like those formulas, and DON'T review those......

 

[CuriousRambler]

I don't disagree @JackD342 - there probably isn't any need to teach the tables, or even the formulas. I also understand the differences in eLearning vs. the book course, so there's equally little need to repeat that point ad nauseam. In fact, I've repeatedly pointed out in this thread my own mistake in thinking the elearning was the right choice for me.

Despite that, I still believe it's a disservice to divers to not even mention the topics at play behind the scenes. Is there a need to cover them in any depth in an introductory course? Probably not, and again, it's most likely of no interest to the vast majority of divers taking the course. I also don't see what harm there would be in adding literally 2-3 minutes to the overall course length to simply mention "you can double check the numbers your computer produces using these formulas." Heck, even a footnote that specifically states you're not required to know the information, but here it is if you're curious. I guess I don't understand the strong reaction to suggesting this info may have a place in the course material, when it could easily be included without any substantial addition to the course, and no more challenge for the "I want the bare minimum to do this safely" crowd.

I work with a bunch of PhDs (for clarity, I am not one. Not by a long shot). Engineers and physicists, mostly. I've yet to meet one of them who knows all the formulas and equations for everything they do, and I'm guessing the ones who remember every formula from school are even harder to find. Where they get their power is simply by virtue of knowing a tool exists. When the situation arises that you need to accurately calculate spherical abberation of a lens to match experimental results, you can either attempt to reinvent the wheel, rely blindly on tools developed by others that may or may not account for all of your factors, or you can say "hey, I think I read an article that somebody already derived an equation that does this" and go dig up that information. If you were never introduced to a hammer, you could spend an awful lot of time trying to drive nails with a sponge.

 

[Whitrzac]

I took the padi course a few months ago(in shop, not elearning). We went over using tables and had test questions on how to use them properly.


There seems to be a lot of finger pointing and blame game going around in the scuba community. It's up you you get what you want out of the class.

 

[ScubaWithTurk]

@ScubaWithTurk , you sound like the guy I want as an instructor haha. I had watched this youtube video a few months ago, calling Dalton's Triangle the "magic circle." I honestly don't get along with math all that well, but given how basic this is, I think it's worth covering.

I have to admit I fully screwed up on this course selection. I know from past experience that online education isn't something I enjoy, or do particularly well with. Tried that in college. Exactly once. So there's honestly a chance I just didn't absorb some info from the eLearning that I had hoped to catch. But I also should have known to expect a "lightened" coursework compared to what might come from a more technical agency, and again by taking the online (i.e. more convenient) course in the first place, rather than pushing for a sit-down, physical book and classroom experience. That's all 100% on me.

I've been texting back and forth with my friend/instructor, and we're going to dive into things a bit deeper once I get out there. When asked about getting a copy of the tables, his response was "Those are for baby boomers and people who don't know smartphones exclusively."

I would be happy to be your instructor. The math for the triangle is easy and we all have smartphones with calculators.

I don't disagree @JackD342 - there probably isn't any need to teach the tables, or even the formulas.

I disagree about a need for the formulas. At least for Dalton’s Triangle.

Why do students need it? So they plan to do a dive say, 30 meters. In order to find the ideal gas for a PO2 of 1.4 at 30m, you need the formula. Maybe you ordered 32% from the DC but you get there and analyze the cylinder to find that it is a bit oft. It is 31% or 33%. Maybe they forgot to blend for you and ask if 28% is acceptable for the dive you are doing because they have a few cylinders with that mix in it. You can use the triangle do decide. If it works, great. If you find it doesn’t for the planned dive, maybe you change dive sites. But knowing how to do this is key to being a safe and thinking diver!

 

[Diving Dubai]

I would be happy to be your instructor. The math for the triangle is easy and we all have smartphones with calculators.



I disagree about a need for the formulas. At least for Dalton’s Triangle.

Why do students need it? So they plan to do a dive say, 30 meters. In order to find the ideal gas for a PO2 of 1.4 at 30m, you need the formula. Maybe you ordered 32% from the DC but you get there and analyze the cylinder to find that it is a bit oft. It is 31% or 33%. Maybe they forgot to blend for you and ask if 28% is acceptable for the dive you are doing because they have a few cylinders with that mix in it. You can use the triangle do decide. If it works, great. If you find it doesn’t for the planned dive, maybe you change dive sites. But knowing how to do this is key to being a safe and thinking diver!

But, but ,but - cheat sheet on phone with 1.2, 1.4 & 1.6 MoD

However in all seriousness. Important to Understand computer and Pure Daltons does't always match.

Eg. Some computers suggest you round down, others you round up

On my Suunto for instance MoD for 32 on Comp is MoD for 33 from calculations as they put a
contingency. So if you're at max MoD by the calc you could spend the whole dive with your computer bleeping or arm in the air.

But I do agree everyone shoudl understand the principles, and even if they can't remember the formula, know where to find it and how to use it

 

[Aviyes]

Unless a student is planning on moving into the Tech realm, they will brain dump that equation as they will most likely never use it. Especially, if they are a vacation diver, as most dive resorts/LOBs that provide Nitrox don't oxygen blend but use the membrane system and it is typically all around 32%, at least everywhere I have gone.

It all comes down to what the student has planned in their diving future, which they need to discuss with their instructor.

 

[Marie13]

Am I the only one who keeps a photo of the Nitrox table on my phone - not the dive planning tables, but the one for finding MOD, etc.? First of all, I’m diving locally and getting my own tanks filled at the shop. No surprises on the boat. I either dive 32% or 28%.

 

[HKGuns]

Having just finished the PADI EANX course, I feel like I fully understand the use of Nitrox as well as the risks involved and the prudent actions to prevent those risks from becoming incidents.

It isn't exactly rocket science. While I freely admit, I may be ignorant, but for recreational NDL diving I don't see a good reason to over complicate things.

I've also taken advantage of a pretty significant number of YouTube videos that treat the subject of tissue loading in great detail. There is a doctor from Australia who does a great job going into a lot of the theory.

 

[Lorenzoid]

You don't really NEED to have the formulas for MOD, best mix, etc. ("Dalton's triangle"?) memorized or handy if you only do these calculations occasionally. If you learned what the variables involved mean in relation to each other in the real world--the principles--which is all I think a Nitrox course needs to teach, then you can feel satisfied that you could derive the formula you need with a minute of thought. Or just look it up and still feel satisfied that you could have derived it if you had given it a minute of thought.

 

[Diving Dubai]

You don't really NEED to have the formulas for MOD, best mix, etc. ("Dalton's triangle"?) memorized or handy if you only do these calculations occasionally. If you learned what the variables involved mean in relation to each other in the real world--the principles--which is all I think a Nitrox course needs to teach, then you can feel satisfied that you could derive the formula you need with a minute of thought. Or just look it up and still feel satisfied that you could have derived it if you had given it a minute of thought.

You're right. Most people in the rec world either use teh MoD displayed on their computers - or know the MoD for their most used mixes.

I do have a PDF of an excel sheet I made on my phone - because..

When I teach it, generally people having dives as well (the boat dives are discounted so its a good deal) so we have plenty of time - they have me for the full day, so we conversationally go over parts of the theory they don't understand or are concerned about.

As long as people know where to find the formula and how to use it, then that cool.

There's quite a few math formula I use occasionally enough as not have them committed to memory - but I know where to find them and how to use them when I do.