Requiring shallow helium mixes?

[RyanT]

Seriously, there are 4 votes for 240+? Yeah, that's about where I start to consider helium a necessity. Can we say troll?

 

[blac86]

Are you a good brainless fundie who never thinks for themself and does everything someone you're paying too much money makes you special and elite - helium at 100ft no exceptions

If you have even two braincells to rub together tho youll know what depth narcosis becomes too big of a factor for you. You'll approach each dive as an individual dive with individual needs and choose the mix that allows you to accomplish all you're objectives efficiently at depth.


Do I need an end of 80ft if all I'm doing is looking at fishes? Do I have complex tasks to accomplish that require mental acuity? Am I a sloppy narc or can I handle myself?

I know I can't tie a clove hitch at 170 feet on air, but I also know I can weld at 145 feet on air.

 

[northernone]

Seriously, there are 4 votes for 240+? Yeah, that's about where I start to consider helium a necessity. Can we say troll?

I met hundreds (rough numbers) of deep air divers, not suprised a few regular this forum. I'm fascinated by the spectrum represented here. Wide variety of the differing training, experience and philosophies backing these numbers.

Underwater the disadvantages of shallow helium are low (none exist?) but I think the above water factors keep our 'need' for it deeper.

Cameron

 

[stuartv]

Underwater the disadvantages of shallow helium are low (none exist?) but I think the above water factors keep our 'need' for it deeper.

Cameron

No doubt. If it were free, I would use it on any dive deeper than 100'. Maybe even dives deeper than 80'. Like you say, there is no disadvantage (that I know of - other than needing a separate drysuit inflation system).

 

[blac86]

No doubt. If it were free, I would use it on any dive deeper than 100'. Maybe even dives deeper than 80'. Like you say, there is no disadvantage (that I know of - other than needing a separate drysuit inflation system).

Helium will eventually bend you on traditional tables. Even modern computer manufacturers admit they add cheats to their deco program for helium dives. That's the underwater downside.

 

[100days-a-year]

Fascinating, happy you are willing to give us a look at what has been working for you. Would you be willing to spit this into it's own thread? I suspect the discussion may be very interesting... brace yourself.

Cheers,
Cameron

I don't think it would be a good idea to split it off as it would appear to condone this kind of diving.Which I don't.These are profiles that will likely lead to DCS short term and DON in the long for anyone who tries them without following all the protocols we use to offset the exposure.We do it cause it's a living.

 

[stuartv]

Helium will eventually bend you on traditional tables. Even modern computer manufacturers admit they add cheats to their deco program for helium dives. That's the underwater downside.

Do you have any links to documentation of this? I have never heard that before.

AFAIK, most trimix computers use published algorithms (e.g. Buhlmann ZHL-16C or VPM-B) and, at least with Buhlmann, Helium has its own set of M-values and there is no "cheat" that has to be programmed. The helium is simply modeled using its parameters, which are different than the nitrogen parameters.

Also, what tables are there for diving with helium? My training for diving on air or Nitrox included use of tables, but my training for using helium did not offer any tables at all. All dive planning to use helium was done using computers.

 

[blac86]

Do you have any links to documentation of this? I have never heard that before.

AFAIK, most trimix computers use published algorithms (e.g. Buhlmann ZHL-16C or VPM-B) and, at least with Buhlmann, Helium has its own set of M-values and there is no "cheat" that has to be programmed. The helium is simply modeled using its parameters, which are different than the nitrogen parameters.

Also, what tables are there for diving with helium? My training for diving on air or Nitrox included use of tables, but my training for using helium did not offer any tables at all. All dive planning to use helium was done using computers.

As to tables I meant using helium on navy tables or other organizational tables is a bad idea.

Look up "helium penalty" to read straight from shearwater or ratio what they have to do to make helium.diving safe.

 

[stuartv]

As to tables I meant using helium on navy tables or other organizational tables is a bad idea.

Look up "helium penalty" to read straight from shearwater or ratio what they have to do to make helium.diving safe.

Does anybody dive helium using tables? Has anyone in this thread even suggested such a thing?

I have read Shearwater's helium penalty article. It doesn't say anything about programming cheats into a computer. What it actually says is that the current models often produce longer deco times when using helium, but it appears to be the case that that is actually good and lucky for us divers because the same dive on just air/nitrox would result in an unsafely short deco profile.

IOW, (according to recent NEDU data) there is no (practical) difference in off-gassing for helium versus no-helium. But, what we actually need, to be safe, is the longer deco profiles that are produced when you tell the computer you're using helium.

Where is the "cheat" programming that's added to anything? Do you have a link to a Ratio article that supports your statement?

 

[blac86]

Does anybody dive helium using tables? Has anyone in this thread even suggested such a thing?

I have read Shearwater's helium penalty article. It doesn't say anything about programming cheats into a computer. What it actually says is that the current models often produce longer deco times when using helium, but it appears to be the case that that is actually good and lucky for us divers because the same dive on just air/nitrox would result in an unsafely short deco profile.

IOW, (according to recent NEDU data) there is no (practical) difference in off-gassing for helium versus no-helium. But, what we actually need, to be safe, is the longer deco profiles that are produced when you tell the computer you're using helium. ?

No I'm saying there is a downside to helium and suggesting otherwise is disingenuous.

That supports my point. Deco times are artificially lengthend for helium because you'd bend otherwise.