Tri-Mix Agencies?

[Graeme Tolton]

In post 19 i replied to this:



I dont see the machismo BS as helpful or productive and so i responded to that in a way that I saw fit on an online discussion forum, by calling him out on it. You are right most of the posts surrounding that were civil and eventually gave much of the information the OP requested. Nothing much happened in the thread after that for awhile.

The OP responded poorly later, and welcomed harsh criticism OR silence.

The rest of this has been a debate that I can only comment on from admittedly very little experience. However, i stand by my opinion that adding helium doesn't necessarily require an arsenal of experience at first. It has become clear that while many here are referring to all trimix diving, especially deep diving, while my assumption is that it doesn't necessarily have to be deep and can be used for non- mandatory decompression diving.

Regardless, many good points have been brought up here, which has allowed me the opportunity to consider many things that I had not before.

Sorry for wasting your time in this aimless discussion.

I am just stating it like it is. If you don't like it don't read it. I stand by my statements. We are all trying to promote safety in our sport, that is why we center you out to try and help you see that experience is absolutely necessary. If you are too thick to see that, god help you because we certainly can't.

 

[hg frogman]

I actually agree about diving 30/30 recreationally, that the bar should be lower.
Anyone with the equivalent of a fundies pass who can just manage to pull off doing *some* amount of deco between 30 and the surface, without shooting straight up from 100 feet, should be able to dive trimix recreationally.
And that probably has 50 dives as a minimum requirement, I can see that no problem.

You believe that someone with 50 logged dives would have enough control, in any circumstances, of his/her ascent rate, to dive safely with Trimix 25/25 ?

Where I live, a normoxic Trimix certification is required by all dive operations to dive Trimix 25/25. So that's just the opposite point of view.

 

[lamont]

You believe that someone with 50 logged dives would have enough control, in any circumstances, of his/her ascent rate, to dive safely with Trimix 25/25 ?

Where I live, a normoxic Trimix certification is required by all dive operations to dive Trimix 25/25. So that's just the opposite point of view.

recreationally, i think divers with between 50-100 dives *can* know enough to be able to dive safely within recreational limits with 25-30% helium in their gas, yes. the average 50 dive diver i would say doesn't know enough (and i probably didn't know enough back when i had 50 dives), but the existence of a 50-dive diver that knows enough to do that is at least plausible to me.

 

[Blackwood]

You believe that someone with 50 logged dives would have enough control, in any circumstances, of his/her ascent rate, to dive safely with Trimix 25/25 ?

Where I live, a normoxic Trimix certification is required by all dive operations to dive Trimix 25/25. So that's just the opposite point of view.

Really? Do the dive ops analyze your gas and ask for appropriate qualifications?

 

[waterpirate]

Oh this is just great!! One more thing to worry about, the mix police.
Eric

 

[hg frogman]

recreationally, i think divers with between 50-100 dives *can* know enough to be able to dive safely within recreational limits with 25-30% helium in their gas, yes. the average 50 dive diver i would say doesn't know enough (and i probably didn't know enough back when i had 50 dives), but the existence of a 50-dive diver that knows enough to do that is at least plausible to me.

Thanks for the precisions. Yes it's plausible. Nevertheless I think that ascending at the right (slow) rate is often more difficult than holding a stop at 6 meters/20 feet or deeper. Worst case IMO is rescuing, i.e. having to bring an unconscious buddy up to the surface: it's already not easy for a Nitrox diver with 50 logged dives, and it's harder with Trimix as the ascent rate is slower and more critical.

Helium may be a better gas for decompression, but Trimix is more unforgiving than Nitrox regarding ascent rates. Trimix is not for the messy diver. Recreational divers should be well aware of this. I am not writing that to start some polemics, but just for safety's sake.

I agree with what you wrote previously about having logged at least 150 dives as a necessary (but not sufficient) condition before getting into Trimix. Here instructors use to say that CMAS *** divers are most dangerous around their 100th logged dive, because that's when they begin to think they are good, experienced divers and can do anything.

Really? Do the dive ops analyze your gas and ask for appropriate qualifications?

No they don't analyze your gas. But if there is an accident (for example a diver ascends too fast with Trimix 25/25 and gets a vestibular DCS hit) the authorities will. Here, diving with a dive operation is ruled by State law, and law forces dive operations to ask for adequate certifications. And lying (even by omission) to a dive operation about your gas and your certifications is not only cheating (for which I have no sympathy): here it's a crime. One may also get in trouble with the insurance.

On the other hand, if you dive by yourself (I mean not with a dive operation) in France, either from the shore or from your own boat, you can do what you want. You may get sued if your less experienced buddy dies, but you are still free to get fills and go diving even without any C-card.

 

[TSandM]

Oh, I don't think there is any question that you have to have better control in the water column than a lot of people have, to dive helium safely. But I'll also say that BOTH of the recreational triox classes I took were as intense as technical diving classes, and included a lot of stress in midwater, and I didn't even get signed off the first time, because I couldn't demonstrate a sufficient level of control to satisfy the instructor. I would certainly hope that the people who are teaching such classes hold those kinds of standards, in which case the use of helium for deeper recreational dives makes perfect sense, if you can afford it.

 

[waterpirate]

There is absaloutely no reqason to withold helium at rec levels. I think the number of dives has to be drawn somewhere and fifty is as god a place as any. As Lynn alluded to, you still have to be accepted into the class and meet standards for a card. If you can satisfy those requirements at fifty dives, giddy yup. After you recieve your card it is up to the individual diver.
I am sure gladd that the U.S. has managed to continue to keep big brother out of diving. I feel there are enough agencies and instructors to continue to self regulate.
Eric

 

[Blackwood]

If 50 is as good a place as any, then why not make it 1?

 

[TSandM]

Well, there is some amount of experience one probably has to have, to make it LIKELY that one has the control necessary to pass a class. What that number is is probably unknown (and subject to a bell curve distribution, too) but agencies choose a figure to help reduce the number of people who would apply to take a class when they were hopelessly unprepared to pass it.

In my experience, in Puget Sound, in dry suits, people with under 50 dives are almost never going to have the control to dive helium. Between 50 and 100, some will and some won't.