PADI Nitrox Course

[ppo2_diver]

I will be taking PADI's Enhanced Air course in two weeks. I've read through the book and did the knowledge reviews. Is there anything in particular that I should really concentrate on for the exam? Any help would be appriciated. Thanks.

 

[salty]

I just practiced the formulas. You will proably never use them agan with all the computer softwear that does it for you after your certified but you need to know the basics.
I took the TDI basic course but used the padi book and took that test and it was easy enough read the book once or twice and like I said review the formulas and how to use them.
Good luck and have fun

 

[MechDiver]

It's just basic math. Remember the "triangle".

Phil

 

[Walter]

Not help for the exam, but that particular course doesn't include the concept of best mix. If he doesn't add it, ask your instructor to explain it to you. It's not in the text.

 

[MechDiver]

Walter once bubbled...
Not help for the exam, but that particular course doesn't include the concept of best mix. If he doesn't add it, ask your instructor to explain it to you. It's not in the text.

That's a nice thing to be aware of, but from a practical standpoint for someone doing basic rec EAN dives, not necessary.

Phil

 

[Cave Diver]

jhnsndn once bubbled...
I will be taking PADI's Enhanced Air course in two weeks. I've read through the book and did the knowledge reviews. Is there anything in particular that I should really concentrate on for the exam? Any help would be appriciated. Thanks.

Pay attention to the wording of the questions. The math problems specifically tell you what tables to use (air, ead, etc.).

Some of the multiple choice questions are not worded well, so read and understand what exactly is being asked before you answer.

 

[Drew Sailbum]

Walter once bubbled...
Not help for the exam, but that particular course doesn't include the concept of best mix. If he doesn't add it, ask your instructor to explain it to you. It's not in the text.

Not quite right there Walter. Best mix is a covered topic. It is simply an algebraic rearrangement of the oxygen partial pressure formula presented on page 85 of the PADI Enriched Air Diver Manual. Same concept, only a different way of presenting it.

Of course it is nice to go into a dive shop and order a custom mix for the planned profile. If the analyzed result of the fill is off a bit from what you wanted, you must either recalculate the dive plan for the fill you received, or refill the cyclinder. (All PADI covered topics)

Part of the recalculation is to determine the maximum and contingency depths for a given mix. This can be done using tables (with a bit of rounding), or more precisely with formulas. (All covered PADI topics)

The nomenclature "best mix" raises a few concerns. The name implies that such a mix is superior to other mixes for that given depth. While the "best mix" does provide for the longest no-deco limits, it does not come without concerns. The "best mix" is one which provides the maximum oxygen exposure for a given depth. While it is important to know where these limits are, it is not necessarily a good thing to push these limits.

 

[Walter]

Drew,

I don't have a copy of the text, but I have searched it and was not able to find this topic. I asked Mike Ferrera to look since he teaches it. He covers it in his class, but was unable to find it in the text. I'll borrow a text and check the reference. Thanks for the info.

The entire reason for using nitrox is to either increase bottom time or to increase your safety margin with regard to decompression status. Unless you use the "best mix" you are wasting the opportunity. PADI, and the other agencies of which I'm aware, deal with the concept of not pushing limits quite well. Limit your PPO exposure to 1.4 or 1.6 for emergencies. Watch your oxygen clock. I personally teach my students to plan for 1.4 at the hard bottom. Diving the walls in CI, that would mean passing on nitrox. Staying aware of the limits of the oxygen clock and staying at 1.4 PPO keeps divers from pushing the limits. Sounds like scare tactics to me. Understanding a concept is always a good thing.

 

[Walter]

MechDiver,

From a practical standpoint, best mix is very useful.

 

[MechDiver]

Walter once bubbled...
MechDiver,

From a practical standpoint, best mix is very useful.

I didn't say useful, I said necessary. And, for most divers, in most situations, in most locations, it isn't practical either.

Phil