Why do dead bodies float on water?

If you killed an average person and dumped the body in a lake, it would sink (assuming that the person did not have excessive fat deposits, which are less dense than water). After a few days of sitting in the water, water penetrates most of the body, equalizing the density, so that the buoyancy is approximately equal to its depth. After rigor mortis begins to cease, all sorts of strange chemical reactions start happening. For instance, all of your cells comtain an organelle called a proteosome. The proteosome is filled with a chemical similar to hydrogen peroxide. When cells die not of their own will (necrosis), the proteosome will eventually rupture, and begin oxidizing anything it touches. Some of the byproducts create gases. As gasses collect and the water washes away the more dense byproducts, the body becomes less and less dense until it can float on water.In the sea/ocean, saltwater is actually more dense than freshwater, making it easier for things to float on them.Live bodies most certainly float on water, if they are fat enough. Fat is less dense than water. Fat people actually float quite easily. Ironic.Muscle is more dense than water, so muscular people sink in water. Of course they can take a large lungful of air to offset the sinking effect, but it sometimes isn't enough. I for one, sink like a stone in water.If a person has a mix of fat and muscle, it is actually possible to find a buoyancy point, wherein the person "floats" at a certain depth in the water.

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