My AN/DP/Helitrox course

[Jack Hammer]

it could happen if they just had a colour coded system and no further ID but im referring to taping the reg and marking it as you do a bottle - that way you can actually see what it is as you're breathing it -
you have the bottle marked and the reg marked and as long as they both match i cant see an issue

A lot of things are easy when you only have one or two bottles. Why create procedures that have to be relearned as you progress? I swap regs around all the time. The contents of a bottle dont change if you swap to a different reg set or swap 2nd stages.

 

[lermontov]

A lot of things are easy when you only have one or two bottles. Why create procedures that have to be relearned as you progress? I swap regs around all the time. The contents of a bottle dont change if you swap to a different reg set or swap 2nd stages.

what relearning process is involved? i tape the reg and mark it the same as whatever is in the tank the hose colour or reg type is irrelevant -its an extra check, you make its sound overly complicated

 

[KenGordon]

what relearning process is involved? i tape the reg and mark it the same as whatever is in the tank the hose colour or reg type is irrelevant -its an extra check, you make its sound overly complicated
View attachment 591997

I think the point is that this markup is either pointless, because you always check they cylinder and the MOD, or an extra way to make a mistake by relying on the regulator markup having made an assembly mistake.

 

[rjack321]

I couldn't agree more!

AN should be a stand-alone course that covers what it claims to be: All the consequences of breathing rich mixes under water up to pure O2. You need to know the consequences, and nobody in any agency ever mentions this:

Pulmonary atelectasis in anesthesia and critical care
Long story short, pure O2 in an alveoli will be consumed by the body and the alveoli will collapse. A bit of nitrogen will prevent this from happening.

https://bjanaesthesia.org/article/S0007-0912(17)44801-X/pdf

“These results confirm both the reduction in lung volumes shown in our previous studies [19, 24] and the results from other studies in which subjects breathed 100% oxygen. This study confirms the work by Green [13], who showed that addition of 20% and 40% nitrogen to oxygen reduced the tendency for alveolar collapse to occur. The present study was more detailed, and showed that there is a log linear effect produced by adding nitrogen to an oxygen mixture up to a concentration of 75 % nitrogen. With the addition of increasing nitrogen to the gas mixture, the reduction in lung volumes caused by breathing oxygen at a reduced lung volume was lessened, and finally neutralized. When lung expansion with deep breaths was encouraged towards the end of each study, several volunteers noticed sharp chest pain which limited their deep breaths. This confirms other experiences [6-10].”

(Is this why 'air breaks' are indicated in O2 treatment?)

On the other hand, DP should (and does) tell you how to properly manipulate said mixes. AP stand-alone is totally valid, but it REALLY, REALLY needs a serious re-work...

Because you aren't going to get pulmonary atelectasis while swimming around recreational diving.

 

[rjack321]

what relearning process is involved? i tape the reg and mark it the same as whatever is in the tank the hose colour or reg type is irrelevant -its an extra check, you make its sound overly complicated
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Why have 3 different checks when you really only need one reliable one?

Ps regs get swapped around, or moved to different bottles and your system breaks down.

 

[lowviz]

Because you aren't going to get pulmonary atelectasis while swimming around recreational diving.

No? @grantctobin, @rjack321: It isn't something that I worry about but it is something that I like to be aware of: https://bjanaesthesia.org/article/S0007-0912(17)44801-X/pdf

How does this affect me and my diving habits? I'm careful not to shallow breathe when on oxygen. Nothing more, but it is enough of a concern that it should be mentioned.

 

[rjack321]

No? It isn't something that I worry about but it is something that I like to be aware of: https://bjanaesthesia.org/article/S0007-0912(17)44801-X/pdf

How does this affect me and my diving habits? I'm careful not to shallow breathe when on oxygen. Nothing more, but it is enough of a concern that it should be mentioned.

Because it doesn't affect your diving at all. Students only retain a fraction of the information in a class - flooding them with superfluous information is not helpful as you are never quite sure what they will actually retain. So there is no reason to include a discussion of something that isn't relevant because they could very well remember the irrelevant bits and forget something that does actually affect them diving-wise.

 

[lowviz]

Students only retain a fraction of the information in a class - flooding them with superfluous information is not helpful as you are never quite sure what they will actually retain.

I see your point and I won't persist on this.

Just consider an alternative, a course dedicated to the handling, under-water use (dive planning), and health consequences of all concentrations of oxygen. They could call it AN, and you still can't dive pure O2 until you learn the mechanics in DP. BUT, you can get oxygen fills and it is up to the student to have the self-discipline to keep it on the surface. Teach that too in AN.

Self-discipline is the heart of tech diving. How many divers who aren't planning to go tech go past Nitrox I?

 

[kensuf]

Doesn't just the fact that it's green make it distinct? As long as all your regs aren't green of course.

Color coding regs is not an excuse for skipping the bottle check. What happens if when you're on the boat and you pressurize that reg you blow a seat?

1. Are you going to rebuild the reg right then and there?
2. Not dive with your bottle?
3. Grab a spare reg from someone (or your spares kit) and go?

If option #3 is a possibility, what are the odds that it'll be green?

 

[kensuf]

That is scary. One of the critical aspects of teaching tech is instilling a discliplined mindset. If some instructors are ignoring this from the outset it's just sending the message that it's OK to cut corners. Not good!

I know PADI Tec has it's detractors, but it's the only PADI manual I've seen that explicitly tells students not to proceed if they lack discipline and gives instructors free range to refuse students who they feel aren't suitable, regardless of base diving skills and qualifying criteria.

Every agency I'm an instructor for allows me the option to not pass a student (or refuse a student) that aren't prepared for the course they're interested in. All of them require that I ask myself "would I let this person dive with a loved one at this level?" before I can issue them a cert.