(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.
At the same time, without circulation to keep it moving through the body, blood starts to pool and settle. Rigor mortis, or a stiffening of the body, sets in about two to six hours after death [source: Marchant, Middleton]. While the body as a whole may be dead, little things within the body are still alive. Skin cells, for example, can be viably harvested for up to 24 hours after death [source: Mims].