The other day I used a couple of lift bags to move a boat mooring out to deeper water at a lake in Maine. Did not have to bring the mooring granite pads (two of them) to the surface, just needed to get them buoyant enough to move about 15 feet farther out from the dock. All in about 20 feet of water. Interesting (and eventually successful) effort, but it was trial and error as we went along. It also got me thinking about lift-bag use in general and lifting more substantial things than a couple of 130# round granite pills. Anybody have some good "does and don'ts" or some stories from people with lift-bag experience?