(klÅt) n. 1. A thick, viscous, or coagulated mass or lump, as of blood. 2. A clump, mass, or lump, as of clay. 3. A compact group: a clot of trucks blocking the tunnel's entrance.
Bodies start to float once the gas from decomposition replaced the  water inside the lungs. It is effected by the depth and temperature  or the water. In warm water it can bâ¦e as soon as 1 to 2 days in 80  degree water, or as much as 14 to 20 days in freezing cold water.
Then, as their body decays and gases expand, the body floats to the surface -- LibertarianLaw]    A submarine or a ship can float because the weight of water that it displaces is equal to the weight of the ship.