why helium?

[Bismark]

sorry, ya lost me.
Do you wish to contribute to this thread?

I believe you may have misinterpreted the OP's question. I don't believe he was referring to using HE in recreational limits but was questioning the use of HE in diving mixes in general. If you look at the experience of the OP I believe it would be a fair stretch to think they were interested in the rec/tech narcosis/HE debate. If I am indeed correct, then it would be safe to say that your answer was less than complete and that was what was surprising to me considering the information was coming from a trimix instructor.

In answer to your questions from the PM: Yes I am trimix trained, yes I regularly dive trimix, and yes I do dive trimix in the upper limits of the recreational range.

To the OP: there is a long standing debate regarding the use of Helium in depth ranges between 100-150'. The subject is one that will be sure to get heated quickly and many people maintain very strong opinions. You can easily Google this subject and spend the next month or so reading personal anecdotes ad nauseum. Good Luck and lay in a supply of gatorade.......

 

[wedivebc]

Good Luck and lay in a supply of gatorade.......

or kool-aid depending on which side of the debate you swing

 

[Bismark]

That was actually pretty funny so you must not be too narced.... I guess you must use enough HE in your Meg to keep your END set somewhere around 100'

 

[Meng_Tze]

Hey Dave and Meng, a bit of a hi jack here, but do you guys use He at recreational depths with your rebreathers, since you're using less of it and it's more affordable, or do you switch out to air diluent for recreational depth dives?

Rec CCR depths I do air dil.
On OC I do nitrox to about 35-38m. Then I start doing mix. But each to their own

 

[lamont]

Also helium is a limited resource and as we have witnessed lately the cost will be coninuing to rise.

at some point the price will get high enough that it'll be easy for oil and gas companies to make the argument that they need to invest in the necessary plant to capture helium instead of just bleeding it off, then the prices will come down.

 

[Bismark]

As for the view that people are willing to accept the higher risks of diving air at depth rather than pay for helium, I wonder if they would also prefer to use older parachutes with an increased likely hood of failure but at a cheaper cost rather than pay the extra costs for a new parachute rental or just stay home that day. The argument for choosing not to dive mix because it is too expensive is pretty silly really. You can always stay home. If I can't afford to rent a plane with seatbelts I won't go flying.

 

[DA Aquamaster]

As for the view that people are willing to accept the higher risks of diving air at depth rather than pay for helium, I wonder if they would also prefer to use older parachutes with an increased likely hood of failure but at a cheaper cost rather than pay the extra costs for a new parachute rental or just stay home that day. The argument for choosing not to dive mix because it is too expensive is pretty silly really. You can always stay home. If I can't afford to rent a plane with seatbelts I won't go flying.

That analogy is patently misleading. Personally, I have never seen any difference in the rental cost of a new parachute versus and old one and if the old one is still certified, there is no significant difference in terms of reliability.

Of course if you get to the tech equivalent of skydiving, you will be packing your own primary chute (the reserve is rigger packed every 180 days by FAA reg) and will have by then probably invested the $4k-$5K for your own rig.

A better analogy is a skydiver who does 100 jumps per year because he owns his own stuff, packs his own chute and is paying only for his share of the jump plane and is consequently a lot better at relative work than the guy who rents and does maybe 10 jumps per year you perpetually stays at about the same level as a newby fresh off a static line.

In the water at 130-150 ft, I'd much rather have an experienced buddy with 50 plus deep air dives in the last year than a mix breathing buddy with 5 or 10 trimix dives in the last year. The difference in currency, experience and skill goes a long way toward offsetting the downside of not being on mix. The reverse is not true as trimix does not cure a lack of currency or experience any more than a new parachute will make an inexperienced skydiver better or safer.

In flying, skydiving or technical diving, if you cannot go often you need to seriously rethink whether you should be going at all.

 

[wedivebc]

As for the view that people are willing to accept the higher risks of diving air at depth rather than pay for helium, I wonder if they would also prefer to use older parachutes with an increased likely hood of failure but at a cheaper cost rather than pay the extra costs for a new parachute rental or just stay home that day. The argument for choosing not to dive mix because it is too expensive is pretty silly really. You can always stay home. If I can't afford to rent a plane with seatbelts I won't go flying.

Your whole argument is based on the assumption that there is an increased risk. It is my belief that the risk is no greater diving to 130ft on air than diving the same on trimix. If you have any statistics to prove diving recreational depths is safer please provide them.
I agree some people are more succeptable to narcosis, mostly heavy breathers. I am not one of them so I don't see the risk at a personal level either.
I do believe diving trimix adds other risks that outweigh the narcosis potential which also factor into my opiion of this. So rather than look at just cost I am considering cost, risk, availablity, training requirements and requirment to carry offboard suit inflation as just some of the factors weighing my opiion that recreation depth trimix is a waste of time. As I have indicated above since I am already set up, trained and have helium in my shed I do use trimix to recreational depths in my rebreather. I just don't advocate trimix for the masses.

 

[Bismark]

The argument between deep air diving and using trimix has been beaten to death and I for one have zero interest in trying to convince those who have already made up their minds regarding this. Simply put, the preponderance of scientific evidence clearly shows that no one "adapts to", "learns to tolerate" or "becomes accustomed to" narcosis any more than you become "adapted" to the effects of alcohol. Impaired is impaired. Period.

Dave, I absolutely agree with you that that anyone using HE requires a significantly higher level of skill to use it safely. However, in the vast majority of cases this can be accomplished by training and learning and practising those requisite skills. Yes for me to it is a question of risk assessment but I want to start my problem solving and dealing with an emergency 100% in the game. Further, I believe it is incorrect to look at the HE/narcosis debate without also bringing mentioning the further benefits of easier WOB and less chance of C02 buildup which is a real killer. I am not telling you anything you don't already know here I am sure, but since their are no absolutes in how a particular person responds to these issues from day to day (cold, fatigue, illness, mental stress....etc) one day's air dive to 130' may not be anything like the next day's air dive to 130. In my version of risk benefit, I prepare for the worst and pretty much enjoy evrything else.


Aquamaster, If I read your argument correctly, you said that you would prefer to dive with in the 130-150' range with someone who has done it 50 plus times in the past year rather than with the trimix diver who has only done 5 or 10 dives in the last year. You are of course entitled to your opinion but I wouldn't dive with either of them anymore than I would get in the car with a drunk drive who had successfully negotiated our route home while intoxicated the last 50 or so times. For that matter I wouldn't drive down a dangerous winding road with someone who was either just new to driving or had not been driving for a long time.

Anyways, like I said earlier this subject has bean beaten to death so I am done here.

 

[shellbackdiver1]

at some point the price will get high enough that it'll be easy for oil and gas companies to make the argument that they need to invest in the necessary plant to capture helium instead of just bleeding it off, then the prices will come down.

I work for the one of the 2 largest special and bulk gas companies in the world. We got lots of gas divers need. We got lots of He. I checked our sell price price to 3 different groups of customers (small, med and large volume). Hasn't really changed in years. Not in sales so I dont know how dive shops are getting it.