Can some explain to me what PPO2 is?

[archman]

I believe NAUI characterizes deep dives starting at 60 or 65 feet. As for using a deep dive in order to "get narced," I find that highly objectionable, and it certainly has not been a component to any dive instruction I have received or taught. I think the Navy makes it part of their program, but that's it.

From what I recall narcosis effects vary from person to person just like DCI, and can occur at any depth (the effects are simply known to increase with depth). The recent results quoted from the Croatian study would be the first substantial thing I've yet heard, but I'd like to know what the details of their tested personnel (age, demographic, physical condition, etc.). In any event I would be very loathe to take a class down deep for the purpose of "learning them" the pitfalls of narcosis. I could just see the lawyers swarming in if an accident happened. You'd need some super hefty waivers and Johnny Cochrane.

 

[divemed06]

Cutting corners....it works for some students and not for others. When I took my Rescue Course, I was hoping to have a chance to practice numerous emergency situations. Unfortunately, the instructor only did the absolute minimum to cover the course requirement. Most of the other students were happy because they got the card in a relatively short period of time. I on the other hand would have enjoyed doing 20, 30 or even 40 situations instead of the 6 or 7 we did... I guess that might be the difference between someone who wants to take a course and someone who wants to learn...no better no worse, just different interests I guess.

 

[DeepScuba]

Truva

60ft is the "depth limit" (official??) of a PADI OW diver.

Man you'd think narcosis was "Real Bad" at 30-40ft the way people and agencies talk nowadays.

Hey I'm all for limitting Narcosis, but c'mon. To even waste time looking a narcosis at 30 ft is, uhm,.........a waste of time.

Ditto for 80-100ft. We dive in $hit (literally) and I don't see too many "Royally Narced" people.

What's wrong with a slight buzz, perceived or real?

Shoot, some think I'm narced at 1 ATA!!!!



Flame away......but how many regularly feel ANYTHING worth noting on an 80-100ft dive?

I've done MAYBE 25-30 dives this year less than 100ft. The rest have all been regularly 115 to 130 (all air) and several upwards to 200ft, and I feel I am more susceptible to narcosis than the average person.

 

[jonnythan]

The student's eyes truly glaze over from the information overload, Wendigo.

The text has a photo of a bottle of tonic water fizzing. That is normally the starting point for the discussion of the theory of decompression, Walter. They can relate to that.

Maybe it's because you simply assume your divers are complete imbeciles who never made it to 8th grade science.

My instructor was a pretty bright guy, and he presented all the gas laws to my (SSI) class in a clear way. The few people in my class who didn't already have a good understanding of the physics involved learned it quickly.. probably because Brian (my instructor) didn't assume we were dopes who can't relate to anything but a bottle of soda.

 

[IndigoBlue]

Maybe it's because you simply assume your divers are complete imbeciles who never made it to 8th grade science.
.

Jonnythan I do present the Daltons Law material, and ppO2 and ppN2 materials.

The main reason is to give them an understanding of their depth limits.

I will teach them they are OK as new divers to dive to 50 ft, and that they should not dive deeper for awhile. Then I show them what happens when they dive deeper.

I recomend EANx for 50 to 100 ft. In our store, the EANx is usually a part of AOW, together with deeper diving to 100 ft, night diving, and advanced navigation.

I will give them the NOAA postulated ppO2 of 1.4 for diving, and show them how to compute it.

I lose most of them, at that point. Its not on the test either for basic O/W.

They always give me the same look of "why are you telling us this when we don't 'need' to know it?"

 

[jonnythan]

I will teach them they are OK as new divers to dive to 50 ft, and that they should not dive deeper for awhile. Then I show them what happens when they dive deeper.

What happens when they dive deeper?

I will give them the NOAA postulated ppO2 of 1.4 for diving, and show them how to compute it.

Why show them how to compute it if they're not going to be using it?

 

[Wendigo]

As Walter said, "I'd rather err on the side of caution and provide more knowledge and skills so my divers will be better prepared for the unexpected."

I couldnt agree more. Being is prepared for the unexpected means knowing what could happen as a result of decisions you make under the water. I dont understand how anyone on the this board could say that less inforamtion is a good thing, at any cert. level.

jonnythan -

Why show them how to compute it if they're not going to be using it?

That has to be one of the most dangerous attitiudes concerning diving I have ever heard.

There's not a lot that anyone is going to say that convinces me that skipping or skimming fundamentals is a good idea. It may save time, but not divers.

 

[IndigoBlue]

As Walter said, "I'd rather err on the side of caution and provide more knowledge and skills so my divers will be better prepared for the unexpected."

I couldnt agree more. Being is prepared for the unexpected means knowing what could happen as a result of decisions you make under the water. I dont understand how anyone on the this board could say that less inforamtion is a good thing, at any cert. level.
.

When we finish physics and they understand P = D/33 +1 and PO2 = FO2 x P then I will give them a comprehensive diagram of diving depths and gas choices.

0 to 50 ft is air

50 to 100 ft is EANx

100 to 150 ft is EANx or Helitrox

150 to 185 ft is normoxic TMX

185 on down is hypoxic TMX

PO2 is an issue beyond 50 ft on EANx, and I show them the calculations.

PN2 is an issue deeper than 100 ft depth, and I show them the calculations.

When I tell them "this is not on your test, by the way" I lose every one of them on the calculations. The discussion mostly just helps them understand why they should stay shallower than 50 ft while they are basic O/W divers.

 

[grazie42]

Saying that you err on the side of caution when giving students more information then required (or, as some would argue, useless to them). Like others have said before, attention is in finite supply and spending it on things that you do not need for OW-diving is not being cautious! Its quite the opposite, IMHO. These things will be taught as they become relevant to the kind of dives you are supposed to do...some might argue that new divers dont always follow these guidelines. To that I say: Spend more time in class and elsewhere teaching them to respect the guidelines! I actually think that that kind of information incourages new divers to feel that they are qualified to dive beyond limits as they "already know all about it"...

Just my 2 cents, feel free to disagree...

 

[DeepScuba]

heehehhe

When the poop is hitting the fan...... Amonton.......isn't gonna save me.

And it don't matter HOW I re-jig his formula!

hehehheh

Save the info for when it becomes relevant. What's the PO2 of air at 60ft?

We have been speaking OW diver all along, I think this is still the parameter.

Show ehm the can of soda, They're learning to dive for the first time, remember?

I'd sooner see emphasis on the more basic of things.

Basic I say?? Ask MHK what's lacking in Basic OW.