The human body is composed primarily of water, and thus has a very similar density. But since only roughly 70% of the body is water, it is slightly less dense than the surrounding water, which exerts a buoyant force on it. Thus, staying afloat requires only a slight propelling of water downward relative to the body, and transverse motion only a slight propelling of water in a direction opposite to the direction of intended motion, due to generally low hydrodynamic drag. This propelling is typically accomplished by cupping the hands and using them as paddles, and by kicking the legs to push water away from the body.


Click Here to read the entire article...