Ok it's a commercial and not a movie but I didn't see a catagory for comercials.

When John Jameson looses a cask of whiskey off the ship and goes in after it, I think there was something far more valuable than whiskey in the cask. If it were only whiskey the cask should float. Pure water is lighter than sea water. Alcohol is lighter than water and wood is lighter than water.

Can the Mythbusters see is a cask of whisky will sink or float? The hard part will be figuring out what John Jameson really had in those casks.