re: #96 doppelganglander

Wouldn’t it just stay the same? The cannonball is

displacing the same amount of water whether it’s inside the boat or at the bottom of the pool.

That is correct.

re: #88 maddogg

While in the boat, the cannon balls displace their weight in water, when tossed into the water they sink, displacing their volumn. Since iron is more dense than water, the water level will fall.

That is incorrect. The amount of water displaced is always equal to the weight of the object, whether it is floating or not…