My AN/DP/Helitrox course

[MichaelMc]

So, my AN manual came this afternoon and I read it.

- There must be a different manual for women as the text only references male divers, though there are pictures of women divers. Chapters one and two are covered with his and he for student and instructor. Though after that it switches to their. Seriously jarring in 2020. Copyright 2009-2013 v1018.
- The course provides for gas switches: "A diver may simply want to have the option to use oxygen for his safety stops during recreational sport dives." Intro p9, "During the course, gas switches may be conducted." Dive Protocols p75. But no discussion of how to safely do them.
- Other than rebreather discussions, I think everything in its 98 single column pages was in the 103 double column pages of my NAUI basic nitrox manual, and NAUI does not start Arabic numbering the pages until after the table of contents and preface, instead of TDI's numbering with the front cover. It is needed for the class, so I now have it. Argh.
- Hmm, what do the PSIA, IANTD or other manuals look like?

 

[Marie13]

Gas switches are covered in the Deco Procedures manual. Or check out Mark Powell’s Technical Diving: An Introduction.

MODS is the TDI shorthand for a gas switch.

 

[ChuckP]

So, my AN manual came this afternoon and I read it.

- There must be a different manual for women as the text only references male divers, though there are pictures of women divers. Chapters one and two are covered with his and he for student and instructor. Though after that it switches to their. Seriously jarring in 2020. Copyright 2009-2013 v1018.
- The course provides for gas switches: "A diver may simply want to have the option to use oxygen for his safety stops during recreational sport dives." Intro p9, "During the course, gas switches may be conducted." Dive Protocols p75. But no discussion of how to safely do them.
- Other than rebreather discussions, I think everything in its 98 single column pages was in the 103 double column pages of my NAUI basic nitrox manual, and NAUI does not start Arabic numbering the pages until after the table of contents and preface, instead of TDI's numbering with the front cover. It is needed for the class, so I now have it. Argh.
- Hmm, what do the PSIA, IANTD or other manuals look like?

There is a whole lot of nothing to advanced nitrox.

 

[Marie13]

There is a whole lot of nothing to advanced nitrox.

Isn’t that the truth! Well, except the accursed math. There is that!

 

[tmassey]

Isn’t that the truth! Well, except the accursed math. There is that!

Dumb question: how is the math for AN different than Nitrox? I’m sure you had to do new math problems, but isn’t it the math exactly the same? (I’m too lazy to go look at my book, but from memory, I can’t remember *any* new math.)

 

[Marie13]

Dumb question: how is the math for AN different than Nitrox? I’m sure you had to do new math problems, but isn’t it the math exactly the same? (I’m too lazy to go look at my book, but from memory, I can’t remember *any* new math.)

I took the basic SDI computer Nitrox class the month after I was certified in 2016. So, no math!

 

[lowviz]

how is the math for AN different than Nitrox?

You have something new to track, OTU's. Oxygen toxicity (in general) is conveniently divided into two bins. The one we all know about is keeping your oxygen pressure below ~1.4 ata so that you don't convulse. This is acute toxicity. Nothing new.

Over time, breathing high concentrations of oxygen begins to irritate the lungs. This is chronic toxicity. It results in lung irritation. I'll leave this to the dive med types to explain in more detail.

So you do have more math, not terribly complicated, just new due to something additional that you have to track.

IMHO, There is most likely an interaction between your OTU's and the max PPO2 that you should dive, but I've never seen it discussed...

 

[tmassey]

You have something new to track, OTU's. Oxygen toxicity (in general) is conveniently divided into two bins. The one we all know about is keeping your oxygen pressure above ~1.4 ata so that you don't convulse. This is acute toxicity. Nothing new.

Over time, breathing high concentrations of oxygen begins to irritate the lungs. This is chronic toxicity. It results in lung irritation. I'll leave this to the dive med types to explain in more detail.

So you do have more math, not terribly complicated, just new due to something additional that you have to track.

IMHO, There is most likely an interaction between your OTU's and the max PPO2 that you should dive, but I've never seen it discussed...

All of that was 100% covered in my Nitrox class. Now I will fully admit that I completely forgot all of that probably hours after taking the class — and that was probably no doubt also because I don’t think we spent 15 minutes of class time on it. It’s not really an issue with 32%, like ever. Of course, I didn’t take that newfangled computer only Nitrox class… I want to say that I took Nitrox in 2006? 2007? So it wasn’t like it was forever ago. (Though maybe the fact that I think 13 years ago isn’t that long ago just demonstrates my age…. Where does the time go?)

To me, the advanced Nitrox class could just as easily be relabeled Nitrox refresher class. Of course, no one would pay for that! (Or maybe, given the computer only classes, it should be called old school Nitrox class? ) It really is necessary, though: because of all of those things that have no application at 30% that suddenly have lots of application at 100%. But it’s not much of a value as a standalone class if you had a decent Nitrox class.

From a math perspective, Trimix class is almost the same as well. The math is the same, you just have to do it twice: once for oxygen and once for helium. I imagine that’s probably true for the helium portion of @Marie13 class, too. Actually, now that I think about it, maybe that’s why she was commenting about the math? That really would change the math from straight up Nitrox class.

 

[Marie13]

It’s the math as a whole! I hate math. I joke that’s why I was a journalism/political science major.

The last time I had done similar math was my freshman year of college - the fall of 1987!

 

[lowviz]

All of that was 100% covered in my Nitrox class. Now I will fully admit that I completely forgot all of that probably hours after taking the class — and that was probably no doubt also because I don’t think we spent 15 minutes of class time on it. It’s not really an issue with 32%, like ever. ...//...

Agree. It isn't an issue until you get into rich mixes.

...//... To me, the advanced Nitrox class could just as easily be relabeled Nitrox refresher class. ...//...

Or OTU refresher class?