I'm Buoyant !!!

I was told that I'm very buoyant.  I know people who just plain sink.  It doesn't mean they cannot swim, it just means they have to adjust their technique to compensate for it.  So in this sense I guess I'm kind of lucky.  Of course I thought it was because of my body fat.  Well, it is partly true because bones and muscle are denser therefore contribute to the sinking factor.  However, lung capacity is a factor also since air in the lungs function as an internal balloon.  Skinny people can be buoyant too.

This peaked my curiosity so I did some research on what exactly this all means.  This little diagram is a great illustration of the Archimedes Principle which explains buoyancy.   It involves the density-volume-shape of the immersed body.

• The body will float if the buoyancy is positive (body weight smaller than weight of displaced liquid).
• The body will be suspended if the buoyancy is neutral (body weight equals weight of displaced liquid).
• The body will sink if the buoyancy is negative (body weight larger than weight of displaced liquid).

This explains why babies bob up and down and roll around so easily in the water.  Another good reason to teach them water safety/floating on back while they're very young.