I found this in a PR book. A sailboat is anchored in an enclosed pool. When the anchor is pulled off the bottom of the pool and into the boat: A- the water level stays constant and buoyant force on the boat increases. B- the water level rises and buoyant force on the boat increases C- blah ... "blah blah" D- blah? blah, blah! My reasoning is that the answer is A. The buoyant force will clearly go up because displaces more fluid with an anchor on board. I'm picturing that the anchor displaces 1 anchor-volume of fluid on the bottom of the pool so the water level shouldn't change as it's brought into the boat. Sure the boat will sink a little bit but that water has already been displaced from the anchor being at the bottom .......... hmm, maybe I just answered my own question. I guess if you bring in an extremely dense anchor onto the boat you increase the average density of the boat and it can displace more volume as a boat-anchor system than separately. Any thoughts?