Nitrox Class Without Tables or Math...OK?

[Scared Silly]

While on a recent live-a-board trip to Chuuk I saw about half of the guests at one time or another reading the manual for their dive computer. Myself included as I had just bought a computer that allowed gas switching. A few others also had new computers and a few others were diving Nitrox for the first time, and for others it was it just a refresher. My point here is that IMHO many people do not take the time to learn how their computer works (works as in how to set it to the proper settings and when "violations" take place what the computer is trying to tell them) so making it intergal to the class is I think a good thing as people might really learn how to use it as a tool.

Now about this theory versus application for Nitrox. The formulas for MOD or the inverse best mix are not that complicated - prealgebra. The trick is understanding how each of the parts works, e.g. working PPO2, O2 percent, MOD and what are the implications of each. So to make it really simple:

Working PPO2 goes up MOD goes up.
O2 percent goes up MOD goes down.

Hey no formulas and this is something students can hopefully walk away from the class with along with the implications of each. That said I would at least show the formula and how I simplified it so that students whould have been exposed to the theory but I certainly would not expect them to remember it.

Now the more interesting part would getting students to do this on their computers as if I ask people to find the MOD for 30% at a PPO2 of 1.4 I bet I will get at least two different answers. Why? Because some computers will use different depths of water for 1 atm. Eg. Suunto for example uses 32ft others will use 33ft. So hopefully this would then lead into a discussion with the class about different computers and the variables they use so that when they are diving with someone with a different computer they will know why they are getting different settings. And as part of this I would show how to get the water depth used which would require backing it out of the formula. So my approach would be to expose the students to the formals but then spend time on the application of it using a computer.

So on the surface I can see what NetDoc is trying to do and would say that it seems reasonable. I guess the question in my mind is how much theory versus how much application. But with out more info it is hard to tell from just an advert.

 

[MikeFerrara]

I've said it before, why does a diver diving at recreational depths(-130) need to learn anything about Nitrox at all?

I think what ND is doing sounds like a great idea, I'd take it a step further, quit pumping air, give everyone 32, tell 'em if they go below 120 they die, pat 'em on the butt and let them go diving.
The majority of diving is taking place in resorts, by divers with computers, who only dive a few times a year. I think everyone would have to agree that few use tables or remember how.

The biggest reason divers started using computers was to get a few more minutes of BT. Probably the best reason to use Nitrox is to get a few more minutes of BT. Put the two together and you have more than a few more minutes of bottom time, but not so much that people are going to try for 90 minutes dives or pushing dives more than 10 or 15 minutes, especially in the 80' +/- range, typical resort type dives.

For those of you (or us) that use Nitrox and other mixes to accomplish a COMPLETLEY different style of diving then a bit of math is in order, or you punch the numbers into the 'ole laptop and go.

Nitrox isn't that hard, it's not scary and you really don't have to know anything but how deep NOT to go. After that most divers can dive Al 80's all day long and not have to worry about 02 loading, heck you can probably do 5 a day for a week and not even have to look at your 02 clock.

Go for it ND if I were closer I 'd come watch

Some goog points and another arguement for doing away with the requirement for a special certification alltogether. I'm for it. Just make sure that you add a stupulation on the card limiting the size of tank and stop certifying divers for up to 40% nitrox if you're assumming that some resort will be forcing them to dive EAN32 and you're not teching them to track O2 or to really stay away from MOD's.

My problem with it is that while most divers dive al 80's and many at warm water resorts, I don't think it's at all fair or sensible to assume that our students will be diving that way. Living in the midwest and having learned and taught taught diving here I can tell you that MANY MANY of my dive buddies and former students have never been anywhere near a warm water resort nor have they ever dived under the supervision of a DM or a guiude outside of training. Why cheat our students by making such assumptions about what kind of diving they'll do? Why limit or handicap them so? Teach them enough at each level so they can make up their own mind and are really ready to take their next step, whatever that might be.

I'm so totally disgusted with the attitude of the agencies and so-called instructors with this..."all they need to know is x because all they'll be doing is y" stuff. I can give literally dozens (if not way more) actual in-water real life already happened examples of how those assumptions , while selling diving to more people, are putting divers at risk sometimes resulting in injury or death (but always a PITA). Blame them if you want (buyer beware right?) but they just don't know what it is that they don't know and the dive training industry isn't telling them. They rely on the instructor (and pay him/her) to inform and prepare them and that just isn't happening. They're being prepared for warm water resort diving under supervision whether they want that or not and their not being informed of that slightly important fact. I've seen far too many divers find some of this out the hard way.

Justify it if you want. It's legal, teach whatever non-diving idiot agencies classes you want. Save the sales pitch for the unsuspecting target of your marketing efforts, though, because some of us have seen enough in the water to know better.

 

[MikeFerrara]

They also would not know when the computer died, so unless they have a backup timer and depth guage they are fooked anyway. In the flying game we learned that when flying exculsively on a backup system it was time to find the nearest safe spot to land. There were only a few situations where continuing to the destination was the only option.

Yes but I pointed out that some computers can revert back to 21% FO2 and if the diver doesn't recognize that the PO2 displayed isn't correct they'll have no way of knowing and the computer will be working just fine for an air dive.

 

[tedtim]

Yes but I pointed out that some computers can revert back to 21% FO2 and if the diver doesn't recognize that the PO2 displayed isn't correct they'll have no way of knowing and the computer will be working just fine for an air dive.

Mike,

No argument there. But the reversion back to 21% is not a Nitrox problem - it is a user problem for the computer.

....My point here is that IMHO many people do not take the time to learn how their computer works (works as in how to set it to the proper settings and when "violations" take place what the computer is trying to tell them) so making it intergal to the class is I think a good thing as people might really learn how to use it as a tool.

IMHO this illustrates the point nicely. An analogy is when a new version of a familiar bit of "office" software is installed on your machine at work. It does not always work the same way and the tendency is to ignore training.

People can buy dive computers. This does not mean that they take the time to learn how to use them.

I suggest that there are two different things here. Even if someone knows the Nitrox theory, but does not know how their computer works, they can get themselves in trouble. By the time they have figured it out they may already be in the problem area. If they set the proper FO2 on the computer and use it to plan the dive, then they should know what they are going to do (max depth, bottom time in the simplest way). Once they get into the water, and the FO2 setting reverts, the plan has not changed. If they are then just looking at the computer for depth/time and go deeper than the MOD because they do not notice the FO2 has reverted, they have also forgotten their plan. It does not matter at this point how much of the theory they understand, the execution of the plan was poorly done.

 

[tedtim]

While on a recent live-a-board trip to Chuuk I saw about half of the guests at one time or another reading the manual for their dive computer. Myself included as I had just bought a computer that allowed gas switching. A few others also had new computers and a few others were diving Nitrox for the first time, and for others it was it just a refresher. My point here is that IMHO many people do not take the time to learn how their computer works (works as in how to set it to the proper settings and when "violations" take place what the computer is trying to tell them) so making it intergal to the class is I think a good thing as people might really learn how to use it as a tool.

I had a similar experience a couple of years ago. One of the divers in our group (it was an LDS organized trip) asked me why it appeared that his computer had a significant difference in allowable bottom time than others he was diving with. He asked me because we had the same computer. I took a quick look at his settings. He had the computer set for diving above 5000'. I don't know how he managed to do that. He didn't even know that he had that option.

Not my buddy.

 

[dl348]

Sorry, if a student is incapable of doing 4th grade math, then diving is far to complicated for them. You are welcome to call it snobbery if you want. I call it weeding out the Darwin candidates before they hurt themselves. It's not much of a leap to explain to someone who should already understand that 1 ATA = 33 fsw how to apply Dalton's law.

If you wanted to *add* in how to use your computer while diving nitrox, I wouldn't object to that, but dumbing down the already easy curriculum isn't the way to do it.

Best of luck to you. I'm sure you'll get plenty of students. There is always a surplus of people out there looking for the easy way out.

Algebra is not 4th grade math, it's usually taught in 8th or 9th grade!

 

[Michael Schlink]

Don't get me wrong Mike, I almost always agree with your position. I really don't like or want to see diving training "dumbed down". But where everyone is going to disagree with me is on the multitude of certifications I think we need. I often see the complaints against the "card collecting", the needless classes, etc.

What I think we need is MORE certifications and I think your post suppports my arguement. There are so many DIFFERENT types of divers, diving environments, attitudes and desires it makes it difficult to train all these divers. If you are trained in a quarry what can you know about surf and currents. If you only dive in resort areas why do you need to know anything about cold water, and on and on.

As far as Nitrox goes I think that there are several different courses that could be taught. I know I know, more cards, more classes where does it stop. But I also can understand that there are quite a few divers out there doing a lot of dives, that simply aren't as interested in learning as much about diving as some of us desire. And I think it's still perfectly alright for those divers to enjoy the benefits of Nitrox w/o going through a math class to use Nitrox.

And I'll add, to some of the posters that think that Nitrox is 4th grade math and that anyboby should be able to do it-Your WRONG- I've taught Nitrox to numerous folks that struggled with the formulas-probably for a variety of reasons, but struggled nonetheless-They were/are good divers, loved the sport, math just wasn't a strong point for them. (Some of them make a bunch more money then some of you are ever going to see) I do in my head math that alot of people reach for a calculator for. So what. I have other areas that I'm weak in. I'm a bit of a historian but my wife ocassionaly corrects my grammar (but what does she know anyhoo). Point being that some folks aren't good at cipherin' and they should still be able to reap the benefits of Nitrox
I'l say it again-ND's on to something

 

[The Chairman]

Again,

no one has YET to show how knowing HOW to calculate MOD, EAD and Best mix without the use of formulae is any less safe than using the formulae.

You think it's evil because YOU don't dive or teach that way. You can keep your elitist attitudes: I want to open up diving to as many as possible.

Mike, I guess you teach your students how not to get narced. You have me beat. I am not nearly as Godlike as you. I only teach them to avoid it all together and how to PAY ATTENTION to their gauges, including the various alarms.

 

[The Kraken]

Gentlemen,

It's getting a tad heated in here.

The Kraken

 

[LSDeep]

first of all i teach sdi beside other agencies also. the approach with computer based diving is with sdi not only the (here) so heatedly discussed nitrox course but all sdi courses starting with open water. many of the arguments against it seem to come from posters that never had a look in the sdi manual / any exposure to the course. all the basics are still covered as in any other course. the difference is merely that students are not required to memorize formulas and do calculations with pen & paper / calculator / tables, but actually get to use modern tools (the in the meantime widely used dive computer) to do their calculations. while sdi was the first agency to "get rid" of tables as calculation tools and require a computer for all courses they are not alone this days with their use. naui and gue have the decoplanner software (even agency specific versions of the same software) and padi the truly half *****ed e-rdp. all that shows that the trend finally goes to planning with "timely" tools. from experience i can only say, it seems wiser to teach the "average" diver with tools he will actually uses. just try the next time you have divers to hand them tables and let them plan multible dives - the results will be for a good part desasterous. for anybody with a desire to learn the details and formulas there is plenty of supplemental material widely available and courses like advanced nitrox cover it well.
as for the open water on air / open water on nitrox argument - you basically do your open water course on nitrox 21! even if some like to call it enriched air and define that as a mixture of o2 and n2 higher than 21% (convoluted bull...). i guess i would define the air open water as a relic from times when nitrox was devils gas and people using it were at best lunatics. sure the cert agencies dont really have an interest to combine the 2 and lose the profits from one courses materials and cert fees. if you take an ow class nothing would really speak against doing it on nitrox - the basics are the same and the planning would have to be extended a bit for different mixes (but for that we have the computer again...)