Chuck wrote:

> 7mm neoprene dry suit I wear almost 40lbs of lead . . .

My how perspective can affect things.  I just formulated a lengthy post
regarding why a 27 lb wing would be fine, and when it wouldn't and Chuck
blew it about half out of the water before I even sent it.

There are, however, reasons why both Chuck and I might be correct.  Due to
my different perspective, I presumed a 7 mm wetsuit, not a 7 mm dry suit.
Big difference.  My best estimates are that the combined decrease in
buoyancy during a dive that results from compression of a 7 mm wetsuit and
use of the gas in an 80 cubic foot tank is somewhere around 20 lbs.  A diver
who would be neutral or buoyant with a nearly empty tank at the surface,
will have at least 7 lbs more buoyancy during the dive than they need, no
matter how deep they go.  To need more during the dive would require a
change greater than 27 lbs (ie, I'm off the mark on the buoyancy of the
wetsuit, which is certainly possible)  or an empty tank negative buoyancy of
7 lbs or more (very unlikely for me).  Since a wetsuit regains its buoyancy
at the surface, what will work during the dive, will almost certainly be
adequate at the surface.

Lee