English: When a body sits on the water it will displace an amount of water and if the weight of the water displaced is equel or greater than to its total weight of the body it will float. Every action has an opposite and equal reaction so when the body pushes down on the water, the water pushes up against the body, supporting it. This is also true of bodies completely emerged. If you weigh a brick in water it will weigh less than if you weigh it out of the water, and the difference in weight will be equel to the weight of the water the brick displaced.