Why do some people float and others sink?
Some people float so effortlessly that even when pushed underwater they bob up quickly. Others require constant effort to maintain at the surface. Whether a person floats or sinks is unrelated to their weight on land. A person’s buoyancy in water is determined mainly by the proportion of fat to overall body weight. Ever notice how oil (fat) rises to the surface in a bottle of salad dressing? This is because fat is lighter than water, and in the body, lighter than muscle or bone. Women tend to be lighter in water than men, as they have breasts and an overall thicker layer of subcutaneous fat. Men tend to develop bigger muscles and denser bones. Are women always lighter than men? No. A 95 pound female marathon runner, all muscle and sinew, though not that difficult to hold up in a Watsu, would sink more readily than a roly-poly 250 pound male sumo wrestler, who would float but be cumbersome to move sideways. What is specific gravity? Just another way of talking about floaters and sinkers
