what do the standards say?

[Jack Hammer]

Advanced Nitrox deals with high O2 concentrations up to 100% and goes much deeper into the topics introduced in Nitrox class. Kind of like the difference between cavern and full cave.

I thought the Nitrox class was kinda BS, but slightly useful. I liked my AN class.

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[JohnAd]

Yes, you can also incorporate AN into a full cave program, I would suggest
conducting 4 dives specifically focusing on AN/DP components in addition to
the full cave course (crediting 2 dives from full cave to the AN/DP
portion). This is, of course, a minimum and if you feel additional dives
are needed, that is your discretion.

At the end of the day, the student and I opted to just focus on AN/DP at this time and we conducted all of the dives in what is essentially open-water (OG basin for skills development and then Hudson Grotto for the 130' dives). The student still owes me a skill before he's finished, which will be conducted in OW at some future point.

Notice that the TDI reply includes both Advanced Nitrox and Decompression Procedures, not AN by itself. The two classes are almost always taught together with the skills blended. The standards not only allow it, they come close to suggesting it. That is because the AN course by itself does not include the skill of switching to a deco bottle, but the DP class does. When you combine the two classes, you can blend the gas switching skills from DP into the AN dives.

My understanding (could be wrong) for the separation of the two is to allow someone to get AN certification to use for recreational rebreather dives.

[cerich]

Notice that the TDI reply includes both Advanced Nitrox and Decompression Procedures, not AN by itself. The two classes are almost always taught together with the skills blended. The standards not only allow it, they come close to suggesting it. That is because the AN course by itself does not include the skill of switching to a deco bottle, but the DP class does. When you combine the two classes, you can blend the gas switching skills from DP into the AN dives.

My understanding (could be wrong) for the separation of the two is to allow someone to get AN certification to use for recreational rebreather dives.

Yes, NAUI recently combined the two. I also normally also teach Helitrox with it as well.

[Carl_f]

i did an/dp as an intro diver, so before app/full.

one dive was to be to gold line in lower orange. we ended up turning on time just out of the corkscrew. one was to 150 towards hendley's, so not far past the bedding plane.

Not an instructor but getting there for OW.


AN/DP before Full Cave is not a standards violation because neither is a pre-requisite for the other.


There are actually a couple of different questions that arise from the potential scenarios presented:


1. AN/DP in conjunction with Full Cave (TDI) ... exceeding a depth of 130 ft would be a standards violation by the instructor since that's a condition of the Full Cave standards. As has been stated above, AN/DP can be taught in conjunction with Full Cave and the standards of all courses must be met.


2. AN/DP in overhead while Intro Cave certified ... exceeding a depth of 130 ft would be contrary to the existing certification and not the AN/DP course standards. Now where I am not entirely clear is whether an instructor taking a willing student beyond the limits of an existing certification in a course that is not specifically being related to the existing certification is a violation of instructor standards. I suspect it would be a violation of TDI professional conduct standards (it would be for SSI professional conduct standards of which I am more familiar.)


Having said that, I am not a standards Nazi for courses I take as a student. So, if I was the student above and the instructor was heading down the above path, I would do my own risk assessment and make the call whether I felt comfortable proceeding. (Before AN/DP, I was not confident of my susceptibility to narcosis at 150 ft so I would likely have rejected that dive plan ... even today, I would likely reject it since I have been to that depth for only several dives and would want more experience prior to putting myself in a hard overhead at that depth on air.)


My two kopeks.

[Michael F]

Air is for tires.

[mstueven]

So does this all boil down to a most restrictive / least restrictive argument? Do the standards for teaching vary from the standards for diving?

In the Midwest it isn't unusual for divers to work on their AN/DP or even Trimix certs prior to or simultaneous with their cavern/cave training. Roubidoux is 150' or so after the first dropoff, but I can get in that far on 6ths. Since I'm hauling in my own gas, I may make the first dive on a stage bottle...

What parts of which certifications are the 'limiting factor' and when do they override each other? Does the Trimix cert trump the cave standard depth restriction? Does it change if you're in training as opposed to a completed cert?

[jj1987]

So does this all boil down to a most restrictive / least restrictive argument? Do the standards for teaching vary from the standards for diving?

In the Midwest it isn't unusual for divers to work on their AN/DP or even Trimix certs prior to or simultaneous with their cavern/cave training. Roubidoux is 150' or so after the first dropoff, but I can get in that far on 6ths. Since I'm hauling in my own gas, I may make the first dive on a stage bottle...

What parts of which certifications are the 'limiting factor' and when do they override each other? Does the Trimix cert trump the cave standard depth restriction? Does it change if you're in training as opposed to a completed cert?

As a diver I would say if you're having to reference the standards to figure it out, you're likely making the wrong decision. That goes both ways, too. If an intro diver has lots of experience in OW carrying a stage bottle and wants to use it to have MORE gas for the second dive, I don't see an issue so long as the spirit of the rule is not violated (limiting penetration to 1/6ths of full back gas), even though I'd assume a stage isn't allowed. If a full cave diver has to check to see how deep they can to on air according to another agency to justify exceeding the cave diving agency max END I'd say they're making the wrong decision.

If I were an instructor it would be more by the book as a single accident could wreck my financial future, but as a recreational diver common sense works darn well.

[Rhino]

I first attempted to take TDI AN/DP after PSAI Apprentice, and before PSAI Full, with two different instructors for the cave courses and AN/DP. My AN/DP instructor was not willing to teach that course to a PSAI Apprentice Cave Diver in a cave. It was my understanding the reason was because it would have violated PSAI Apprentice standards regarding stages, both for extending penetration and multiple deco gasses. Said another way, the instructor explained I would have been diving beyond both my cave training certification level (Apprentice) AND my basic diving certification level (Nitrox), and the instructor was only willing to train above one certification level at a time. I may be wrong, but that is my understanding based upon our discussions when 40 Fathoms became unavailable to us.


Frankly, I'm not sure whether the instructor was applying a standards-based prohibition or a general mentality of-"until you're full cave certified, then the only training you should be doing in a cave is cave training." While that may not have been the instructor's meaning or intent, it makes sense to me.

[Aotus]

Frankly, I'm not sure whether the instructor was applying a standards-based prohibition or a general mentality of-"until you're full cave certified, then the only training you should be doing in a cave is cave training." While that may not have been the instructor's meaning or intent, it makes sense to me.

+1

When I wanted to sit in on the survey clinic a while back, when I was at Intro, I was told more or less this same thing, that any added task loading is not ok in the cave until after full cave. Sounded reasonable to me. I was later given the option to attend the clinic as long as I stayed in the cavern. Something else came up and I missed out on it altogether (aaaargh!).

[curtschu]

Air is for tires.

Not anymore what do you think happens to all that great N2 that come out of a membrain system? Capture, recompress and put it in high performance tires. They loose pressure slower and don't change as much from heat..