Yikes,
You all have too much time on your hands!!! How many pages since yesterday??? What's this I hear of Tani borrowing my candiru???
Spook, I think I know the reason you sink... you are so muscular (and we all know that fat floats, so therefore your body must have a greater muscle to fat ratio than most).
Either that or since you say that you are square-shaped, maybe cubes sink???
You can't really be only 5 feet tall? I'm 5'4"...