Former lifeguard here. Here is my attempt at depicting one of the many vareities of aqueous hams. Note that while fat floats (more than muscle/bone at least) a ham's intinct to keep their head above water for easy breathing often means that only their upper body is at the surface (head up = sinking hips, thus why swimmers breathe to side). Also getting most your body to breach surface takes good technique/core strength. https://slimgur.com/image/EYc (Female specimen used because female swimwear is more useful for showing body positioning)