Who's using 100% O2 for deco?

[lowviz]

So, I wonder how many pure O2 users understand that; or, do they just do it because everyone else does and "0%" N₂ sounds good?

If you mean DIR, it is one of the things that I like about them. They force a minimal (NOT always optimal) set of mixes on their practitioners. Some get it, some don't, but all benefit from the "mean".

I like to optimize.

You pays your nickel and you takes your choice....

 

[Jax]

If you mean DIR, it is one of the things that I like about them. They force a minimal (NOT always optimal) set of mixes on their practitioners. Some get it, some don't, but all benefit from the "mean".

I like to optimize.

You pays your nickel and you takes your choice....

Nah, don't want to make it a DIR thing; there are an awful lot of people that do things even if they don't understand why . . . :blinking:

 

[Thalassamania]

If you don't understand it, or at least think that you understand it, I'd suggest that you not do it.

 

[jimmy71]

I kind of did not want to say that but if you do not understand that concept, you do not really understand the concept of nitrox or the different tissue compartments. That said, in the end it is all theoretical anyway.

All deco and tissue models are based on a crap load of assumptions. Even the physiological event of DCS is not fully understood. We know it is not the presence of bubbles in the blood stream as the Doppler studies show that we all have some degree of them after every dive. Concepts and theorys are fluid and have to change with our current knowledge.

I really do not understand gravity but I keep using it all the time. Does that make me dangerous?

 

[gsk3]

We know it is not the presence of bubbles in the blood stream as the Doppler studies show that we all have some degree of them after every dive.

That's a gross oversimplification that denies stochastic causality.

 

[jimmy71]

you are correct. I should have said it is more complicated than JUST the presence of bubbles in the blood stream. Not long ago the definition of DCS was presence of bubbles in the blood stream.

 

[Jax]

If you don't understand it, or at least think that you understand it, I'd suggest that you not do it.

:snicker: That would be good advice for the majority of the populace of the US. However. . . it's just not working!

 

[lowviz]

If you don't understand it, or at least think that you understand it, I'd suggest that you not do it.

I realize that by thanking your thread I can be criticized as inconsistent, -but such is the nature of diving.

 

[ianr33]

But you do incur a much heavier CNS load on the 100%.

You seem pretty concerned about this and I'm not sure why.

Provided you choose a sensible bottom gas (<1.4) It takes a pretty decent dive to get the CNS to go over 80%. Anything less than that and I and I really don't give it a second thought.

I've only done a handful of dives where the CNS was >80. Air breaks seem to be pretty good so far at keeping me alive. I also fudge a little and ease up to 15 feet or so once the 20 foot stop has cleared.

 

[boulderjohn]

For all of my early tech training we used 100%. That training was DIR, and we knew the Baker's Dozen rant, although we did not pay a lot of attention to it specifically.

For a variety of reasons I finished my trimix training through TDI. I was quite amused in reading the TDI textbook about this topic. In the section where they say it doesn't matter which you use, there is a reference to some people "beating their chest" and raving about only using 100% O2, and the way it was written, it was very clearly a direct response to Irvine's Baker's Dozen rant. I sent the Baker's Dozen to my TDI instructor, who had never seen it and was quite amused.

In my TDI training in South Florida, we used nothing but 80%. The local fill shop banked it. I did a lot of dives during that period, and there were always other deco divers on the boats with us. I believe every one of them used 80%.

I will use whatever my team wants to use without giving it a second thought.