Other boats, however, are made of metals such as steel, which are much denser than water. So how do they float? They can because they're hollow, so there is a lot of empty air space inside the boat's hull.
The air that is inside a ship is much less dense than water. That's what keeps it floating! As a ship is set in water, it pushes down and displaces an amount of water equal to its weight.
Liquid can levitate and boats can float upside down in this gravity-defying physics experiment. They have discovered a peculiar phenomenon that allows lightweight objects to float on the bottom surface of this liquid, with a kind of reverse-buoyancy.