yojimboguy and snermy: (What a great, strange name snermy is, by the way.(But what can you expect from someone from Ohio? I’m originally from there myself.)
You’re both obviously some sort of horrible mutants with the lung capacity of Blue Whales.
Of course this post is not meant to be serious and…ah, screw it!
Amaranth, Mirage, Sigene, Turbo Dog: oh man, if you can’t float, you must be dense! 
So just how dense is the average person? All the sudden, I’m seeing this question elevate all the way to one of Cecil importance. Sheer fantasy, I know, but now that we have parsed the question in a smart assed enough manner, perhaps a lightning bolt response will spring forth from the sky.
I sink too. Not like a stone, but I’ll slowly go to the bottom in a pool. Salt water, too. I always have.Totally relaxed, lungs full of air, down I go.
When I was in boot camp (1964), they taught “survival swimming” where you would float on your back while slowly kicking your legs and timing your breathing with a slow sidestroke of your arms. Down I’d go. Actually it was pretty funny. There I was, kicking and stroking exactly as I was told, till I bonked my head on the bottom. 
Really perplexed the instructors though. Perplexed in boot camp equals pissed off. It didn’t help that I came up laughing and snorting with all the other recruits.
Well, I tried. So screw 'em. 
I wonder if they still teach that survival method?
Peace,
mangeorge
i can only float on my back if it is arched unusually high. barring that, first it’s my legs, then the rest of my body to the bottom. (i don’t bother with floating much, since I know how to swim). never could tread water, though. or diving (phobia about going head-first into anything).