Triox for the masses

[Epinephelus]

I think as the long term negative effects of micro bubbling become more apparent to the recreational diver, these gasses will be become less exspensive as a result of the increased use.

Huh?
E.

 

[pants!]

You know how you get tired after air or nitrox dives?

I've heard the argument that this, which is usually the result of microbubbling of nitrogen, actually takes quite a toll on the body over time. Premature aging, etc etc.

I'm not sure how true it is, but reducing the amount of nitrogen in the blood significantly by diving trimix at recreational depths, especially if you do a lot of diving, would be a good idea.

Wouldn't it be funny if we found out that diving air or nitrox towards the limits of the NDLs was really bad for your health? Diving air would be right up there with smoking

 

[lamont]

I think as the long term negative effects of micro bubbling become more apparent to the recreational diver, these gasses will be become less exspensive as a result of the increased use.

The economics doesn't quite work that way. Helium is an expensive gas because its rare, not because there is no demand. Its supply is also constrained by its production as a byproduct of natural gas mining. Assuming recreational divers could actually start using enough Helium to significantly increase demand (won't happen), you'd see the cost of Helium go up. Its economics are more like oil, and less like ethernet cards.

 

[StSomewhere]

Sure, but you don't think supply chain is also part of the problem?

 

[lamont]

Sure, but you don't think supply chain is also part of the problem?

I don't know. Still, you'd be better off trying to get more weather balloons floated to increase demand than try to increase demand through scuba diving...

 

[Sloop John B]

Why not? Why are agencies making it so hard to get triox/trimix cards? Is there something inherently dangerous about it? It seems simple enough as long as you dont mess with the Oxygen levels beyond those allowed by a nitrox card.

I will be taking rec triox in the future as soon as I clean up a couple of skills I personally was not satisfied with in DIR-F. In the meantime I want my gas! Why are they keeping it from me?

Does anybody have a good answer?

I would also hazard a guess that the "masses" generally aren't skilled enough to handle the deco responsibilities that come with Helium.

 

[mer]

I would also hazard a guess that the "masses" generally aren't skilled enough to handle the deco responsibilities that come with Helium.

To recreational depths (i.e. 80-120') there are trimix mixes that mimic the profiles for nitroxx, and mixes that mimic the profiles for air. Granted in DIR, we believe that all dives are deco dives and require "minimum deco" in the form of a proper ascent profile.

It may be true that the greater body of recreational divers would have a problem successfully conducting our ascent profile, but my point is that the profiles and minimum deco for triox is very similar to what people are doing on nitrox.

 

[Brian Gilpin]

I would also hazard a guess that the "masses" generally aren't skilled enough to handle the deco responsibilities that come with Helium.

I see. So the biggest safety factor is the lack of immediate access to the surface with He as compared to EAN or air. Although all DIR dives are "deco dives" He imposes tighter restrictions on ascent rate which basically requires you have the same buoyancy and ascent skills as a true deco diver.Do I have this right?

If so, I can see the need for additional training before cutting people loose with the gas. My Dir-F experience is clearer now that I can see where it is headed. Thanks for the help guys. I guess I will be patient for a while.

 

[rossh]

I think that's probably all debatable.

I'll throw in my $0.02 and then grab some popcorn...

To first order, He and N2 are the same as far as DCS goes. V-planner tends to extend deco stops when you substitute N2 with He which suggests its model thinks that He is "worse" for deco. A lot of people have had success with substituting 50/50 for EAN50 as the 70 fsw gas though without modifying their profiles and 'feel better' when they get out suggesting that He is "better".

Lamont, you may wish to look at the helium in the deco item in my DecoMyths pages. VPM and V-Planner make plans using real gas properties and physics. For the Triox plans being considered here, the NDL's are faster than the same Air versions.

Regards

Ross Hemingway
V-Planner http://www.v-planner.com

 

[lamont]

Lamont, you may wish to look at the helium in the deco item in my DecoMyths pages. VPM and V-Planner make plans using real gas properties and physics. For the Triox plans being considered here, the NDL's are faster than the same Air versions.

Regards

Ross Hemingway
V-Planner http://www.v-planner.com

cool! i think you added that one recently because i checked that page a week or two ago =)

i'll have to play with the general principal that "we deco from the bottom mix" and see if i can see that in the profiles that v-planner generates...

BTW, does v-planner model different half-times for He and N2 for the oil-gas and blood-gas partition coefficients? or do you have any thoughts on the relevance of that to deco models? there's the article out there on *recompression* using 50/50 vs. EAN50 and 100% and they found that because oxygen is actually slow and He is fast for diffusion into and out of free-phase bubbles from/to the lungs -- that there's a sort of isobaric counter-diffusion effect when using 100% on recompression where it enters N2 bubbles faster than the N2 leaves and the bubble transiently increases. That seems to imply that tissue (lipid dissolved) Helium would be good (leaves fast) while free phase bubble Helium would be bad in decompression -- but i don't know how valid it is to start extrapolating studies on recompression to studies on deco...