Posted by Dick Analog on April 11, 2005 at 21:33:19:
In Reply to: Pony posted by Elaine on April 11, 2005 at 20:56:17:
You hit the two trickiest aspects of our pony system, right on the head. On the first dive, we went in with the configuration shown in the photos. The bottle+mounting+regulator combination was a lot more negatively-buoyant than I expected (the bottle itself should have been about 1.5lbs negative when full). We effectively swam around with a 'limp' on our first dive, trying to stay level. It was pretty annoying.
Before our second dive we shifted the bottle to the center of the tank. This solved the asymmetrical weight problem, but the pony bottle became an extremely efficient kelp catcher.
Our next solution was to keep the bottle toward the side, as before, and also remove one of the non-ditchable weight bags from its pocket on the same side of the BC as the bottle. We may take this approach a little further by hanging one of those tank-band-mounted weight pouches on the side opposite the bottle, and take some additional weight out of our general weight system. But, the tank-band-weight is non-ditchable, so there is a limit to what we can safely do. It's still a work in progress.
One positive aspect of the bottle's additional weight is that it helps you stay more upright when you're on the surface with a back-inflated BC.