On 28 Feb 2001, at 13:11, Reef Fish wrote:

> On Wed, 28 Feb 2001 11:03:04 -0600, Mike <[log in to unmask]> wrote:
>
> >On 28 Feb 2001, at 11:01, Reef Fish wrote:
> >
> >> On Wed, 28 Feb 2001 08:22:08 -0600, Mike <[log in to unmask]> wrote:
> >>
> >> >Another thing to consider is what you body is telling you after
> >> >agressive profiles. I think that many divers fail to read the signs that
> >> >their body is giving them.
> >>
> >> There is even a term "bio-feedback" for this sort of listening to
> >> your own body.
> >
> >That's a good term for it.
>
> Not mine, but apparently widely used in other contexts.
>
>
> >> >If you are feeling progressivly more
> >> >"fatigue" after several dives over a few days then you should allow
> >> >more time for your body to recover. This is something that you can
> >> >feel but the algorithm of your computer can't.
> >>
> >> Excellent point to bring out.  EXTREME fatigue (though short lasting)
> >> is one of the unmistakable signs of "marginal bends".  So are
> >> non-lasting shoulder aches, and others.  When your BODY is not
> >> feeling tip-top shape, listen to what it's trying to tell ya.  :-)
> >
> >Term for this is sub-clinical DCS.
>
> Correct.  I was just trying to be informal about it.  :-)

Understand. :-)


> >>
> >>
> >> Here's a lesson *I* learned about computer diving.  The ORCA algorithm
> >> (for no-deco, no gas mix) is unquestionably the MOST RELIABLE and TIME
> >> TESTED algorithm to date.  It had been through millions of dives over
> >> the years by recreational as well as professional divers with no
> >> obvious quirks.  That's why I still carry two, on long series of
> >> repetitive dives on liveaboards.
> >
> >I certainly understand the time tested part of this statement. From
> >wence does the most reliable come from though?
>
> See my preceding reply to Kuty.  From the ABSENCE of adverse reports
> or quirks on the use of said algorithms over billionz and billionz
> of dives (as Carl Sagan would have said) :-).

Got it. I thought that might have been it. Wonder if there have been
any studies about divers using this algorithms and related DCS hits.


>
>
> >> So much for the background.  In July 1997, I decided to do my "wall
> >> research" in Cozumel.  :-)  For 21 consecutive days, my shallowest
> >> first dive was the one to Devil's Throat (130-ish).  The other
> >> 20 days were short bounces to max depths between 190 and 200 fsw. :-)
> >>
> >> On EACH day, I did only two dives, and the "wait to fly" time was
> >> usually around 6-7 hours.  So, to conserve battery, instead of letting
> >> it run till it reach the "turn me off" point, I turned the computer
> >> off each day and re-started on the next day.
> >
> >So the computer did not have the correct information to feed it's
> >algorithm with. :-)
>
> Yes, so to speak.  That the ongoing update was unknowingly TRUNCATED.
>
> But perhaps more importantly, even if it weren't truncated, because
> of the limitation of compartments in the model (12 is about the most
> any model uses today), there is always the KNOWN truncation error
> for the cumulative effect of the extremely slow compartments.

Yep, and that's still true today of many if not most computers. :-)


>
> I think Mike's post was truncated.  It stopped abrupted after the
> last sentence.  So we may have to resume later.  :-)

No, I read the rest of the post. You figured out the problem and
corrected it. :-)