On 17 Sep 2001, at 23:23, Carl G. Heinzl wrote:

> >> > > I suspect that exertion during a dive is as much and maybe more
> >> > > important to post dive fatigue than the gas used.
> >> >
> >> > Possibly. I'm sure it has an impact on it.
> >>
> >> I don't believe the gas will matter much unless you're starting to
> >> talk about a "deep" dive - say approaching 100' or more.  The reason
> >> is that nitrogen loading at the shallower dives plays a progressively
> >> smaller part.
> >>
> >How so? The greatest change in pressure is in the shallow parts and
> >the fast tissues are loading up big time here.
>
> Not true.  The greatest PERCENTAGE change in pressure is near the
> surface, but the change in pressure as we descend is a constant
> roughly equal to 14.7 psi / 33 fsw or .445 psi/ft.

As I responded off list, Carl is correct here, of course. While the
percentage of change is greater near the surface, tissue loading
should be pretty constant at these depths based on pressure
gradients between the inspired gas and the tissue gas. The gradient
will be much greater deeper.

~~~~~~~~~~
Mike Wallace
Huntsville, Alabama