BSAC published new gas density recommendations

[Deep_Down]

For those of you interested:
BSAC recommended diving gas mixtures for open circuit diving

I find it interesting but controversial for two reasons... It may improve (I still doubt it) the safety on one side, but on the other...more He= more $$$ and richer He mixes when switching to Deco gas more possible IEICD...
The second issue may imply an intermediate stage tank, or more deco time because the deco switch should be shallower...
Lets see if these new mixes get standardized in opposition to the current standards of 18/45 or 21/35...among others.

 

[NothingClever]

Kudos to BSAC for codifying Prof Mitchell’s research. Should make for excellent reference material for my dive smart book.

 

[NothingClever]

Lets see if these new mixes get standardized in opposition to the current standards of 18/45 or 21/35...among others.

Good point. I bet the effort to benchmark some new best mixes doesn’t crystallize as much as the densities will. IOW, of the two guidelines, complying with density limits probably supersedes a new mix rubric.

 

[JohnN]

For those of you interested:
BSAC recommended diving gas mixtures for open circuit diving

I find it interesting but controversial for two reasons... It may improve (I still doubt it) the safety on one side, but on the other...more He= more $$$ and richer He mixes when switching to Deco gas more possible IEICD...
The second issue may imply an intermediate stage tank, or more deco time because the deco switch should be shallower...
Lets see if these new mixes get standardized in opposition to the current standards of 18/45 or 21/35...among others.

Is there a way to get to the tables without joining BSAC? I would guess that BSAC didn't entirely fund the research, it seems unreasonable to put them behind a paywall.

 

[Edward3c]

Is there a way to get to the tables without joining BSAC? I would guess that BSAC didn't entirely fund the research, it seems unreasonable to put them behind a paywall.

Having spent the time and resources developing the tables with BSAC members’ money, it’s only right access is restricted to members.

 

[JohnN]

Having spent the time and resources developing the tables with BSAC members’ money, it’s only right access is restricted to members.

Ahh, so you took a study funded by offshore dollars (US$) and compiled some tables, and feel justified in charging for them?

No new research?
Wasn't the study directed at rebreather divers, how was the determination made that it was applicable to OC?

 

[tursiops]

Having spent the time and resources developing the tables with BSAC members’ money, it’s only right access is restricted to members.

I'm certainly glad not everyone feels that way about numerous topics that affect our safety while diving.

 

[NothingClever]

Good gravy, folks....search YouTube and you can listen directly to Prof Mitchell’s work.

And call me crazy but being friendly with our cousins has usually (actually always) benefitted me greatly.

I’m thinking that thumbing our nose at them will probably have the opposite effect of what’s desired.

 

[Deep_Down]

I must say I'm not as happy as some of you with these tables. IMHO increasing the He will increase the price of the mixes, but also is an important driver of IEDCS because of counterdifussion. Now the gas switches will have a bigger PN2 differential, and thats an important factor. The tables estate, i.e. that for a dive to 65msw the He must be 54%. Thats a lot of He when switching to a typical Nx mix. Lets see what happens.

 

[tbone1004]

the talk of ICD and inner ear DCS I thin is a bit misunderstood. Having lower gas densities does not mean that the gas switches are as abrupt. If the gas density is maintained, the ratio of pn2 increase to he decrease should not be any worse than it is with the WKPP standard gases which have a similar limit of 30m/100ft for END which they use based off of 32% instead of air, but it's close enough. This isn't going to cause any wild switches from 12/70 straight over to air as a deco gas which would probably cause some problems. It's literally a monkey see monkey do since the WKPP has had this recommendation out for almost 30 years...