All of this is physics and biophysics. But when you come down to the bottom line, there are two forces: gravity pulling you down and bouyancy pulling you up. The gravitational force on you is really just a function of your total mass. The bouyancy is a function of the specific material of which you are composed.
Thus, the greater bone mass you have, the less bouyant you are; the more air in you lungs, air passages, cavities, the more bouyant you are; fat is less dense than muscle--thus, the more fat on your bod the more bouyant you are. Of course, there is the Archimedes Principle (know in elite circles as the "Bathtub Principle") and that effects your wet suit: as it gets more compressible, it displaces less water and is less bouyant. But it comes down to this: we are all individuals and need to experiment to find our perfect lead (Pb) needs. (By the way Pb stands for lead and is from the Latin Plumbum which means lead and is also wherefrom our work "plumbing" comes; you see the Romans used lead for plumbing!).
I think that most of us find that as we get more experienced, we need less weight. I have assumed that we are less nervous, do less rapid breathing, etc. and that we need to counteract less bouyancy. I am 6 feet 200 lbs and started with 14 lbs. when wearing an O'Niell Fleece and now use 6-7 lbs with the same gear. I almost never have air in my BC--usually only when I have ascended and am waiting to board the boat. I'll bet there is someone my same height and weight who works out everyday and needs no weight at all!
Joewr
Thus, the greater bone mass you have, the less bouyant you are; the more air in you lungs, air passages, cavities, the more bouyant you are; fat is less dense than muscle--thus, the more fat on your bod the more bouyant you are. Of course, there is the Archimedes Principle (know in elite circles as the "Bathtub Principle") and that effects your wet suit: as it gets more compressible, it displaces less water and is less bouyant. But it comes down to this: we are all individuals and need to experiment to find our perfect lead (Pb) needs. (By the way Pb stands for lead and is from the Latin Plumbum which means lead and is also wherefrom our work "plumbing" comes; you see the Romans used lead for plumbing!).
I think that most of us find that as we get more experienced, we need less weight. I have assumed that we are less nervous, do less rapid breathing, etc. and that we need to counteract less bouyancy. I am 6 feet 200 lbs and started with 14 lbs. when wearing an O'Niell Fleece and now use 6-7 lbs with the same gear. I almost never have air in my BC--usually only when I have ascended and am waiting to board the boat. I'll bet there is someone my same height and weight who works out everyday and needs no weight at all!
Joewr
