Wrolf Courtney wrote:

> Ian M. Irvine wrote:
>
> >1) do not expose yorself in open water to a decompression obligation
> >where you could not just keep breathing the known gas to get out ( fear of
deco)
>
> Sounds interesting.  Are you saying e.g. that if I have a bottom mix and
> a deco mix,
> I should have a contingency plan for loosing the deco mix of just
> continuing to
> breathe the bottom mix (for a much longer time).  Or what?
>
> ....snip...--

Yes, that is one bailout method that can be used in some situations. Cut a
table for
deco using only the bottom mix and put it somewhere you can get it if needed.
Make
sure while cutting the table you do a calculation to see how much gas you'll
need.
Make sure you have this amount of gas when you get back to the anchor line
(plus the
min. working tank preasure - 300psi or so) if you are going to really count on
this
method. On some dives its not possible to have that amount of gas on the dive
in the
first place. Still, its good to know anyway, becuase if you can safely deco up
the
line, say at 60, 50, 40, 30, and then signal to another diver/boat to share or
get
(ala Jon) deco gas that will save yourself. For the diving in the NE USA, the
further
up the line you can get the better and that table will get you there.

You also can do this with multiple deco gasses. For instance, using 50/50 and
02 for
deco, I bring extra 50/50 so if the 02 deco source has a problem I have a
bailout
option better than bottom mix. I cut a table for this. I make sure that there is
enough 50/50 so I can get out or at least not make a nusence of myself trying to
crounge alot of 02 from my buddy or others on the hang :-).
I do make sure that I have enough bottom mix at the end of the dive to get by
without
the 50/50. Chances of a problem occuring with both deco gasses is astronomical.
So I
cut a table for that too.

Tom
--
Guns and Armour of SCAPA FLOW
1998 Underwater Photographic Survey of Historic Wrecks
www.gunsofscapa.demon.co.uk


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