Nitrox Class Without Tables or Math...OK?

[jtivat]

So I assume none of you use V Planner or a similar dive planner, and if you do, do you recheck all of the math on paper? As long as a student understands the process I see nothing wrong with a computer giving them the answers. I use V Planner to do my math or even my dive computer to figure MOD all the time it is just easier and faster. I learned to do the math on paper and now use the computer to do the work, so am I not worthy to dive Nitrox? Please listen to your selves!

 

[The Chairman]

Sorry, if a student is incapable of doing 4th grade math,

I suggest that you give the algebraic calculations to a fourth grader to test your fallacious arguments.

Let's get real. MOST divers don't use tables and if you give them a table they have a hard time remembering just HOW to use them. So you want to predicate the entire class on using a tool that they will just leave behind? That's just dumb. It's also short sighted and elitist.

To prove this point, please tell me how being able to make the calculations increases the safety of any dive. Go ahead. I'll wait.

 

[Charlie99]

Is there anything wrong with teaching a course in Nitrox using only a computer? No tables? No math equations to learn for MOD, EAD or PPO2s?

What do you think?

I think that equations are nice, but not necessary. Tables are required, but only to the level of having a general idea of acceptable NDL and CNS loadings, with the primary tracking being done by a computer.

I use calculators and computers to do complicated and/or tedious calculations for me. I DO, however, have a rough idea of what the expected answer is so that if either I or the calculator make a gross error I'm likely to catch it.

I look at diving with a computer (air or nitrox) in the same way. Responsible use of a computer includes having a general idea of what it should be telling you, even if you let it handle the details.

Strip things back to the basic requirements and you only need to know two things when diving nitrox:

1. How long can I stay down and still be able to come back up with a given set of stops/ascent rate ---- for most people, this is just "NDL". Just like when diving air, I let the computer keep detailed track of NDL/N2 loading, and verify it with a general ballpark tracking in my head. For nitrox, either an EAD table, or some crude rule of thumbs (such as "equivalent air depth is about 80% of real depth on EAN32, about 75% of real depth when on EAN36".) along with a standard air NDL table give me enough info for an effective sanity check of what the computer is telling me.

2. What are the CNS and pulmonary oxygen limits? In recreational diving we just ignore pulmonary since for typical recreation diving CNS limits are reached first. CNS time limits can be safely ignored by simply staying below 1.4ata ppO2, provided you don't have bottom time greater than 150 minutes single dive, or 180 minutes per day. If you will exceed 150 minutes, then you need to do a bit more calculation.
Again, a general familiarity with the table CNS ppO2 vs time table is needed, but merely as a validity check of the nitrox computer.

 

[BHB ScubaTroll]

Hi Pete,

I just finished NAUI Nitrox class on Thursday
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If I had known you were going to offer your class, I would have forgone my training for yours.
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With that said, and with all the information fresh in my head from my class. I offer to drive from Tampa to Orlando and sit in on your class and report to all as a student report on the class.

With your permission, of course.

 

[The Chairman]

Permission granted.

 

[BHB ScubaTroll]

Great!

I try to never pass up an opportunity to learn more!

I'll be there

 

[RiverRat]

I have to say I actually enjoyed learning more about "gas laws" etc. in the Nitrox course. Taking the PADI route up to Rescue I don't recall really learning anything much about gas, rock bottom etc. etc. I learned most of that here on Scubaboard during my training (pretty sad I think to have to use the Internet to supplement training, but that's the way it is). Sure you learn the basics about pressure, ascent rates etc. but nothing in detail. Taking the Nitrox course gave me some insight as to what was really going on with my gas, body etc. while diving. I also enjoyed the physiology and physics info I got taking the Divemaster course. I'm sure not all divers are like me. Some just want to learn the basics and get wet once a year. But many of these divers also get hurt because they don't comprehend the whole picture of what is really going on physiologically during a dive. In my 3 plus years now as a diver I've seen 2 people get bent. One was reading her new computer manual in the Van on the way to the boat in Grand Cayman, the other I took to the chamber in North Carolina because of his chain smoking between dives, blowing safety stops, probable drinking etc. I'm so glad I took Rescue because we had a long surface swim back to the boat and he didn't look so good. I felt, had the need arised, I could have calmed him down, towed him in, whatever to get him on the boat safely. Underwater he was not comfortable on that dive (the VIS was down etc.) and wanted to blow the stop (we had to do our ascent at the stern) but I convinced him to do our stop, stay together and I calmed him down. Lucky for him he did not blow that stop or I'm sure he would have been bent much worse. I'm sure my Rescue training helped out on that dive. The point I'm trying to make is that you can't have too much training in this sport. I'll admit, it's easy to get rusty when you start diving Nitrox on a computer but it's great to have all the info in the back of your mind. And nice to know if I blow up the computer I can revert to "manual".

I think if your course is in addition to the current Nitrox course, like an "add-on" then that's perfectly ok. Many people are really ignorant on how to use their computers. Most of them are too lazy to learn I think. I've seen it dozens of times. "My computers red light went on???" "Do you know what that was?" "Why was it beeping???"

So if you teach people to use a computer the way it should be used, and understand how to use it, then that' a good thing. You just may save them from a chamber ride someday or worse. Maybe it would be a good idea to bundle a computer course to the current Nitrox course? You tag it on the end of the course and then have everyone plan a Nitrox dive using the computer. And you run them through MOD, PPO2, Contingency planning etc. I see now the 2 dives are no longer required for the Nitrox couse. Not so sure I agree with that. I enjoyed putting the knowledge to work to plan a few dives. Yeah it was just in a quarry, shallow dives on 28% but I still LEARNED some things planning those dives and it got me in the habit right away of thinking and planning out the dives.

 

[Thalassamania]

At DEMA's first workshop on NITROX (remember this is back when the training agencies, operators and locations thought NITROX was devil gas and we few supporters walked around with tee shirts that had two fried eggs in a frying pan on them and the words, "This is your brain on air.") Bill Hamilton quoted me as supporting NITROX by saying that there were really only three major learning objectives to a NITROX course: breath in, breath out, and control your depth and time. What I actually said to Bill was that I thought most recreational divers could not possibly master the critical learning objectives of a NITROX course, namely: breathe in, breath out and control your depth and time.

Face it, that's all you really need to know, every else is nice to know but not required to effectively use NITROX in a fashion that minimizes risk. To argue otherwise, I feel, requires that you argue for major changes in the conventional recreational diving curriculum.

I, for one, feel that such changes are important and should be made, but that is a separate discussion. I can see no reason for a double standard that says its OK to do thus and so if you're breathing NITROX21, but for 32 or 36 you must do something different.

 

[gcbryan]

Great!

I try to never pass up an opportunity to learn more!

I'll be there

It sounds like you are taking the opportunity to learn less

Seriously, the only argument here is not with learning to use computers which is how most people dive after class. It's with not learning the "why" behind what the computer is doing. I don't understand the point in having a Nitrox class and not including how to figure MOD or optimal mix at least while one is in a classroom situation.

Those not exposed to a Nitrox class might feel that the math is too hard but surely Pete, you as the instructor don't feel that it's too hard to understand so why not include that info along with how to use a computer.

Actually, I think you have to in order for the students to be able to pass the test for any Nitrox course that I've ever heard of.

 

[BHB ScubaTroll]

It sounds like you are taking the opportunity to learn less

Seriously, the only argument here is not with learning to use computers which is how most people dive after class. It's with not learning the "why" behind what the computer is doing. I don't understand the point in having a Nitrox class and not including how to figure MOD or optimal mix at least while one is in a classroom situation.

Those not exposed to a Nitrox class might feel that the math is too hard but surely Pete, you as the instructor don't feel that it's too hard to understand so why not include that info along with how to use a computer.

Actually, I think you have to in order for the students to be able to pass the test for any Nitrox course that I've ever heard of.

Well, let's put it this way...

Most of the responses I have encountered for this thread are VERY quick to judge and post, and VERY slow to put their "money where their mouth is"

I have reserved judgement based on the fact that I have my reservations. BUT, unlike you and others, I will be sitting in the class, and will have 1st-hand knowledge for my critique, rather than spouting off about what I THINK is going on