Diving Nitrox - Do you?

[String]

Originally Posted by Richard Mason

Got no idea, but if not, I'd say it's a reasonable assumption that it would given that it has a lower PPN2, bit like the difference between crashing into a tree at 20mph rather than 30.

Not all "reasonable assumptions" have actual real world effects.

[DAFFY]

Originally Posted by MonkeyPony

My diving is split into 2 halves. The BSAC stuff tends to be 'easier diving' (6 - 35m in general). The other half I dive outside the club system in a select little group for the more challenging stuff (35 -50m) this is all done using appropriate gas planning and run-times.

It’s not that I feel the club isn't meeting my needs but we are spending time and money training divers to use something that no-one bothers to use. If this is not an isolated case and is a general trend within bsac (and/or padi) then maybe its the training that’s the problem.

Sounds like you club is similar to ours. Everybody in the club is nitrox qualified yet only several of us actually use nitrox on a regular basis, it's the usual story club members don't mind spending hundreds on camera/video equipment ect but baulk at the idea of paying out for an 02 clean or the couple of quid more that nitrox costs compared to air, judging by the previous posts it seems quite common across clubs

[SoggyFox]

Originally Posted by MonkeyPony

Dive pairs are not given out before the day of diving to avoid any of that 'I'd rather dive with him/her' buddy-swapping rubbish that can go on. The marshall wouldn't have a clue who was diving what gas before the day sa that is not a consideration when planning the pairs (in our club at least)

fair enough not giving out buddy pairs, we don't normally but in general try and buddy up people who want to dive together but all must understand that its not a right.

does the marshall for the day not give and indication of depth expected?

[Silent Diver]

Almost everyone in our club dives nitrox but it helps that we can supply all gases inc trimix and at a price cheaper than the nearest dive shop.

[MonkeyPony]

Originally Posted by SoggyFox

fair enough not giving out buddy pairs, we don't normally but in general try and buddy up people who want to dive together but all must understand that its not a right.

does the marshall for the day not give and indication of depth expected?

We dont have a club boat so the dives planned and depths are known from day 1.

[nigelH]

Originally Posted by MonkeyPony

Our club compressor cant pump clean air

Is our club just backward?

QED

[Richard Mason]

Originally Posted by String

Not all "reasonable assumptions" have actual real world effects.

Well given that gaseous perfusion/diffusion/whatever is driven by differences in partial pressure of gases, if the driver of gases into tissues (PPN2) is lower, then it's a more than reasonable assumption that the risk is lower.

It's no different to diving on air tables and using shorter NDLs than recommended on the air tables. I'd be happy enough to bet the farm on it. Besides whgich, my Nitrox Course notes said that very same thing. Whatever the effect, it couldn't increase the risk.

[String]

Originally Posted by Richard Mason

Well given that gaseous perfusion/diffusion/whatever is driven by differences in partial pressure of gases, if the driver of gases into tissues (PPN2) is lower, then it's a more than reasonable assumption that the risk is lower.

It's no different to diving on air tables and using shorter NDLs than recommended on the air tables. I'd be happy enough to bet the farm on it. Besides whgich, my Nitrox Course notes said that very same thing. Whatever the effect, it couldn't increase the risk.

Im more than aware of the theory however whether that theory has any real world effect remains to be seen.

As for nitrox courses saying the same thing, some agencies state it (bsac), several dont make the same claim.

Its off topic though now so i'll start a thread in the deco forum later today when i get home i think. If there is any evidence at all i want to read it.

[PeeBee]

Any dive deeper than 15m or any 2nd dive where the 1st was deeper I dive on nitrox as a matter of course subject to MOD. But I do it on air tables to increase the safety factor, as I understand it older people (me) and anyone carrying excess bioprene (me again) are at greater risk of DCS so diving a richer mix reduces my risk.

If my buddy needs my gas he's welcome to share. I'f I'm not sure what the hard depth will be then I might turn up with a weakish fill of say 28% but more usually I standardise on 32%

[Richard Mason]

Originally Posted by String

Im more than aware of the theory however whether that theory has any real world effect remains to be seen.

As for nitrox courses saying the same thing, some agencies state it (bsac), several dont make the same claim.

Its off topic though now so i'll start a thread in the deco forum later today when i get home i think. If there is any evidence at all i want to read it.

Well if it gives you a longer bottom time without increased risk of DCS, how could it not be. All theories are just that, theories, even when they seem to work. Personally, I think you are hair splitting. Can you think of a mechanism where it could increase the risk?