The bodies of the drowned sometimes surface on their own, but this depends on the qualities of the water. The putrefaction

of flesh produces gases, primarily in the chest and gut, that inflate a corpse like a balloon. In warm, shallow water, decomposition works quickly, surfacing a corpse within two or three days.

Does a body float when it drowns?

As a general rule, yes. A cadaver in the water starts to sink as soon as the air in its lungs is replaced with water. Once submerged, the body stays underwater until the bacteria in the gut and chest cavity produce enough gas—methane, hydrogen sulfide, and carbon dioxide—to float it to the surface like a balloon.

When you drown do you float or sink?

When one drowns, the struggle usually knocks all the air from the lungs, allowing them to fill with water. This causes a drowned corpse to sink to the bottom. The cause of drowning isn't water in the lungs, but the lack of oxygen, also known as asphyxiation.