French exception

[d^2b]

How is that trolling?

Both oxygen and nitrogen toxicity limits for air are below 60m.

My concern at those depths would be nitrogen narcosis. Quoting a recent survey [1]

"The effects of nitrogen narcosis are highly variable among divers with all divers being significantly impaired while breathing air at 60 to 70 meters, whereas some divers are affected at 30 meters."

Later they write:

"he effects of nitrogen narcosis are highly variable among divers with all divers being significantly impaired while breathing air at 60 to 70 meters, whereas some divers are affected at 30 meters."

I'm not expert, but that seems to roughly represent the (non-French ) consensus view.

I originally use the word "trolling" because deep air has a long history of flame-wars, going back (at least) to the dawn of technical diving [2].

[1]: Nitrogen Narcosis In Diving - StatPearls - NCBI Bookshelf
[2]: See e.g. Simon Pridmore's "Technically Speaking Volume 1".

 

[JMBL]

My concern at those depths would be nitrogen narcosis. Quoting a recent survey [1]

"The effects of nitrogen narcosis are highly variable among divers with all divers being significantly impaired while breathing air at 60 to 70 meters, whereas some divers are affected at 30 meters."

Later they write:

"he effects of nitrogen narcosis are highly variable among divers with all divers being significantly impaired while breathing air at 60 to 70 meters, whereas some divers are affected at 30 meters."

I'm not expert, but that seems to roughly represent the (non-French ) consensus view.

I originally use the word "trolling" because deep air has a long history of flame-wars, going back (at least) to the dawn of technical diving [2].

[1]: Nitrogen Narcosis In Diving - StatPearls - NCBI Bookshelf
[2]: See e.g. Simon Pridmore's "Technically Speaking Volume 1".

This second post of yours is very accurate, the first one was a bit terse.

Let me please give you my point of view as a French and deep air diver (I've already stated it on SB multiple times) :

Give us access easily to helium while diving and deep air diving will be history. At the moment, helium si too damned expensive, to complicated to get, and local regulations are not helping. Air is everywhere... The real scandal according to me lies in the difficulty of getting O2 for deco. It ought to be easier but in fact, is almost as complicated as getting helium.

No need to start up again a flame war.

 

[rjack321]

The real scandal according to me lies in the difficulty of getting O2 for deco. It ought to be easier but in fact, is almost as complicated as getting helium.

So the M26 DIN is keeping everyone super safe then!

 

[JMBL]

So the M26 DIN is keeping everyone super safe then!

Even with that damned contraption, it's not so easy to find a filling station...

 

[JMarc]

Give us access easily to helium while diving and deep air diving will be history.

I'm not so sure looking at some folks around me (the kind who are doing "une petite 60" from the beach, after works, with no security measures in place; I'm NOT going with them even for saner dives)

 

[JMBL]

I'm not so sure looking at some folks around me (the kind who are doing "une petite 60" from the beach, after works, with no security measures in place; I'm NOT going with them even for saner dives)

Hello JMarc, nice to see you around here.

Each diver does what he sees fit for him. I might dive with those guys : I was trained to do the same : deep air, on a single tank, even to 60 m. Too be on the safe side, you're compelled to rather restrictive bottom times.

I've not done so for quite a while though, if Trimix is not available, I have my pony for deco (3L filled with either Nx60 or 70 depending of what I can get).

But as I have stated : Trimix is damned too complicated to get ! If you're diving with a LDS the price of the dive will be more than doubled, and if you want to dive on your own, getting a filling is almost impossible (not available except in some very special sports, delay for filling the tanks, time to drive there (in the summer that can be an ordeal in itself...). The only solution is to get your own filling station, not so easy either and not so convenient. On the other hand, air is everywhere...

 

[JMarc]

Each diver does what he sees fit for him. I might dive with those guys : I was trained to do the same : deep air, on a single tank, even to 60 m. Too be on the safe side, you're compelled to rather restrictive bottom times.

My issue isn't so much with diving to 60m on air (been there, may do again for the right dive with the right buddies), it's the casualness with which they are doing it (decided on the spot evening dive after a day of work with no security planning). That casualness let me wonder how they are handling security in general. Well some here certainly consider than just doing 60m on air is not taking security seriously.

And that casualness let me think that even if you were offering them trimix training and gaz for their dives and bringing it to their favorite beach, they would still consider it too much of a burden to complete the training.

Although I'm considering it, I'm not trimix trained. Last time I was part in a conversation about that, the LDS said "we can't get helium anywhere anymore, the group which diving with trimix this week brought in their own helium so we can fill their tank", so I'm somewhat aware of the difficulty of doing trimix diving now in France even if you want to.

 

[Adamastor]

Later they write:

"he effects of nitrogen narcosis are highly variable among divers with all divers being significantly impaired while breathing air at 60 to 70 meters, whereas some divers are affected at 30 meters."

I'm not expert, but that seems to roughly represent the (non-French ) consensus view.

I'm no physiology expert either, but my understanding is that the "workaround" for narcosis is a progressive habituation to depth. It is agreed in France that one shouldn't dive to 60m after a long break and resume diving with progressive increments of 5m to the maximum depth.

 

[Angelo Farina]

I'm no physiology expert either, but my understanding is that the "workaround" for narcosis is a progressive habituation to depth. It is agreed in France that one shouldn't dive to 60m after a long break and resume diving with progressive increments of 5m to the maximum depth.

We have the same concept here in Italy.
We simply set the safe limit a bit shallower, around 50-54 meters instead of 60.
But the concept of reaching it in progressive increments is exactly the same, and it is quite effective.

 

[Germie]

Deep air is returning with the heliumprices now. So what they always did in France is now seen everywhere, going to 60m on air. Maybe not a single tank. And people who first sticked to absolutely trimix at 40m (or even 30.1m) are now going to 45m on air, 50m on air, etc.

In 2011 the cmas limit of 3* was 60m, and there fore it was a PO2 of 1.6.
Then they lowered the PO2 to 1.4, which was 57m on air. And now the standards say 40m. So cmas is more or less changing also.
But if you have an older 3* cert, they cannot say it is only 40m now. My cmas 3* is a 60m cert, it is not written on the divemaster card, but it was done in that time. I have also real tech certs, but if needed, I can use my cmas 3* as a 60m single tank on air cert. But I am happy I have other knowledge too.