View Single Post
Unread 07/23/2004, 12:13 AM   #21
Tech Diver
Registered Member
 
Join Date: Nov 2003
Location: Concord, MA
Posts: 310
Quote:
Originally posted by nitroxdiver009
i also stay overweighted so if my buddy decides to go for the surface i can deflate my BC and grab him and slow him down if not stop him.
I understand the logic behind overweighing yourself. However, consider the fact that controlling one's buoyancy requires making continuous adjustments against an inherently unstable system. That is, when you begin to sink or rise you do so at an increasing rate because of the changing volume of gas in your BC. By overweighing yourself you wind up with more air in your BC than you normally would (to counteract the extra weight). So a change in depth affects your BC gas volume by a greater amount resulting in more instability. This extra amount can be fairly significant.

Controlling buoyancy is like balancing a billiard ball on top of a smooth mound; the ball wants to roll off. Lots of gas in your BC makes the mound very steep, while a small amount makes the mound very gentle.

As for pulling your buddy down, the technique I was taught was to grab him from behind, and with your arm across his chest YOU use HIS inflator to control the buoyancy for BOTH of you.


Tech Diver is offline   Reply With Quote