Archimedes's Principle has a lot to do with buoyancy, it explains where buoyancy comes from. Archimedes found that objects either wholly or partially submerged in water displace a certain amount of that water. Furthermore, the objects had a force exerted upon them, in an upwards manner, that was equal to the weight of the water they had displaced. This upwards force is known as buoyant force, or buoyancy. This is the reason people weigh less when they are submerged in a swimming pool. Buoyancy is also responsible for steel ships floating in the ocean; the steel is spread over a larger area, which displaces a larger amount of water. This displaced water pushes back, in return, against the bottom of the ship, helping it to float.