Posted by tleemay on December 20, 2000 at 10:30:16:
In Reply to: Ascent rate question for MHK and TLEEMAY posted by AADIVER on December 19, 2000 at 13:26:07:
Michael answered - so I figured I'd toss in my
input.
Without a BT I use as my own guide the tried and
true physical reference of "no faster that the
smallest bubbles" and cut it at least in half.
This is the best reference available should a
bottom timer konk out during the dive and we are
in mid column without a down or anchor line. As
Michael pointed out already, if we want to monitor
our ascent rate electronically, the Uwatec timer
has that functionality built into it. For the most
part though, I do not rely on the BT as the primary
monitoring point of my ascent, I rely on it more
to ensure I'm at the proper depth for the schedule
stop during the ascent.
Idealy, I try to maintain about a 1' every 2-5 seconds
if possible... even slower if we are coming up on a
deco schedule that mandates an obligation of many minutes
in the 30'-20' range. Since proper gas management
was calculated and the bail-out procedures were layed
out in advance of the dive, we have more than enough
of the proper media to breathe during the longer
stops - and much longer ascent rates. For proper
outgassing, slower is better. Flatter is better
too - but that's another topic.
Sport dives are handled the same way with the exception
of maybe the use of a single cylinder and no deco
gass vs duals and up to three more cylinders. The
ascent rate I describe above is also used for every
single tank/shallower/shorter duration diving I
currently do.