and are usually floor mounted. They can handle drills up to 2 inches in diameter, which mount into tapered Morse sockets. Larger workplaces are usually clamped directly to the table or base using T-bolts and clamps, while small workplaces are held in a vise. A depth-stop mechanism...
Assuming that the top one will be buoyant to that x-altitude chosen, all the ones below add to the upthrust power. This is a observable fact, we agree on that I am sure. Like with any spar buoy one portion of it will "float" out of the fluid from which is buoyant the other ...