Mo2vation:We at GUE (Glorious Underwater Exposure) have formulae for this, but I don't want to go into them in detail on a public board like this one. Our instructors cover all of this (in our class, PIXL/f) in great detail. I suggest you sign up for PIXL/f and we can teach you precision molecular buoyancy and calculating average exposure on the fly.
is there a cert for this