Should TDI Helitrox replace AN+DP?

[helodriver87]

All due respect to John, I think he's dead wrong. There's nothing precluding me from understanding the concepts behind gas selection and narcosis management. If you come out of a T1 course and all you know is that GUE says 18/45 between 150-200 and that's just the way it is, your instructor needs to find another job. I can fully understand the factors that contribute to narcosis and how modifying my gas properties will affect that and still choose to dive standard gasses for other, very valid reasons. The education argument holds zero water for me.

I love the idea that he'll dive air to 200 if he can control everything, as if that's even possible. John comes from the New England wreck diving school. They accepted helium use about as grudgingly as possible. Dress it up however he wants, he's advocating for a narrower safety margin for no real benefit.

 

[CAPTAIN SINBAD]

John comes from the New England wreck diving school. They accepted helium use about as grudgingly as possible.

Why though? What exactly was the opposition to Helium? It was not as expensive back then as it is now.

 

[helodriver87]

Why though? What exactly was the opposition to Helium? It was not as expensive back then as it is now.

General distrust more than anything. They're strangely attached to deep air for some reason. Seems to be a cultural, tough guy mentality thing.

 

[seeker242]

While introducing his Trimix class, John Chatterton writes the following:: IMHO, there are important lessons to be learned by diving air to deeper depths (around 180'), prior to assuming the additional responsibilities of deeper dives on more complex gas mixes.

I've yet to see any reasonable explanation of what these alleged lessons are and why they're important.

 

[helodriver87]

I've yet to see any reasonable explanation of what these alleged lessons are and why they're important.

It's like learning to drive. The first few times you're behind the wheel, the instructor makes you do it drunk so you can learn the importance of driving sober.

Anyone? No? Just an Oklahoma thing maybe?

 

[ChuckP]

Maybe you all ought to take a class with John, catch up with him in the shop or on a boat - he will answer, talk about or explain his line of reasoning - he’s just a normal guy teaching deep diving.

I’ve spoken with a few different instructors before I took the advanced classes - old school is not something I’d personally describe him as - other instructors yes but not him.

The cost of helium is absurd, it’s got to be something really special for me to pay for those fills. The way I dive daily, believe what you want, narcosis is manageable - it’s real for sure but manageable. CO2 is a bigger enemy for me. You guys diving in the deep cold working, I could see the problem you have - it’s your choice to dive those conditions.

I just see that in the future, OC diving beyond 170’ is going to fall out of favor due to costs.

 

[helodriver87]

Maybe you all ought to take a class with John, catch up with him in the shop or on a boat - he will answer, talk about or explain his line of reasoning - he’s just a normal guy teaching deep diving.

I’ve spoken with a few different instructors before I took the advanced classes - old school is not something I’d personally describe him as - other instructors yes but not him.

The cost of helium is absurd, it’s got to be something really special for me to pay for those fills. The way I dive daily, believe what you want, narcosis is manageable - it’s real for sure but manageable. CO2 is a bigger enemy for me. You guys diving in the deep cold working, I could see the problem you have - it’s your choice to dive those conditions.

I just see that in the future, OC diving beyond 170’ is going to fall out of favor due to costs.

You can't separate CO2 and narcosis. They go hand in hand and are directly correlated to your depth and the density of your breathing gas. Turns out, helium addresses that too. Deep air is old school, period. We know better now, but some people still teach it. Some of it is out of stubbornness or an outdated mentality. Some of it is because people are cheap. Neither is a good enough reason, IMO.

 

[ChuckP]

IMO - learning the broad spectrum gives you more knowledge - then of course you have to think and analyze on your own as to what is the best choice for where you want to go.

Teaching deep air only or teaching helium only are equally bad methods of teaching.

 

[rddvet]

IMO - learning the broad spectrum gives you more knowledge - then of course you have to think and analyze on your own as to what is the best choice for where you want to go.

Teaching deep air only or teaching helium only are equally bad methods of teaching.

Deep air is dangerous, as is teaching deep air. More correctly, discussing deep air while teaching trimix or some form of it is the appropriate answer. In my opinion, an instructor taking a student on a deep air dive is asking to eventually have a bad day.

It's obvious you've got your opinion set in your mind, and that's fine. Just realize that it's an antiquated view and helium is becoming the norm for most agenies at depth. You're welcome to dive how you want to dive as long as you're not hurting anyone or getting a dive site closed. If we were on a boat doing a 150 ft dive and you showed up with air, I'd sure as hell stay way far away from you.

 

[helodriver87]

Teaching deep air only or teaching helium only are equally bad methods of teaching.

No disrespect intended, but that's some serious "both sides are the same" BS. One is dramatically and provably safer than the other. If it's too expensive, that's your choice. But pretending that those are even remotely comparable is a joke.