Posted by Joe R on August 31, 2001 at 22:02:39:
In Reply to: Volume matching posted by New Tech Guy on August 31, 2001 at 15:04:11:
volume matching if done correctly, in theory allows the buddy team to have
a gas supply available from their buddy should they have a total gas failure.
the critical point is the turn point where 1/3 or the gas has been used.
if a failure occurs here, and the return is more difficult or takes
longer the gas supply may be inadequate.
volume matching is used to account for dis-similar tank sizes and
breathing rates.. the worst case is the diver with the larger
tanks also has the higher breathing rate. if they both reached 1/3
use 1/3 at the same time and the higher breathing rate larger tanks size
has a total gas failure this could be a problem. in this case
the person with the smaller tanks and breathing rate woould actually
have to turn their dive BEFORE reaching his thirds.
YOu basically have to figure out how much gas is necessary to
get the diver with the higher breathing rate covered.
This will be your finaly reserve volume and will determine your
turn PSI.