I do a lot of diving in the quarry, because I have not yet convinced Uncle Pug to adopt me (if adopted the first thing I would do is repaint the pink boat). In the quarry, sometimes you have to look hard for amusement. One of the most fun activities Ive come up with is to dump all the air out of my BC at the surface, descend head first as fast as possible, and just before getting to the bottom going horizontal and flaring, adding just enough air to get as close as possible to the bottom without actually touching it or stirring up the silt and coming to rest there a foot off the bottom.
If your going to try this I have a couple of suggestions. First find out how fast you can equalize and dont descend faster than that. Second, practice on the platform, so if you loose control itll be a controlled crash.
Have fun,
Mike