There is this show “Weapon Masters” – I think it comes on the discovery channel. It is not a bad show. The basic idea is that they have this history guy talk about the historical aspect of some type of weapon and this other guy tries to make an improved version. Last night the goal was to recreate the original flame thrower mounted on a boat.
They found a boat and they needed to test it’s sea worthiness. The builder guy (sorry, I don’t know his name) estimated that they would have 1000 lbs of equipment in the boat. To simulate this weight, they put 4 guys and two barrels of water in the boat and motored around.
After a little bit, the history guy noticed one of the barrels was leaking water. *”Quick! Put your finger in the hole before we all sink!”* he said. This is where he doesn’t understand floating. I think I can explain his error with two simple pictures:
The first picture has the boat with the water in the barrel. The second picture has some water that has leaked out. Either way, the total mass of water in the boat is the same. If you would like to talk more about floating, [here is my post about MythBuster's lead ballon](http://scienceblogs.com/dotphysics/2008/09/mythbusters-how-small-could-a-lead-balloon-be/) – same idea.
I think the weapon master history guy should have said:
*”Quick! Plug the hole before my shoes get wet! But, we won’t sink because the mass of water is the same no matter if it is in the barrel or in the boat.”*