Visible signs and characteristics. 1  There is a noticeable break in the pattern of the waves: the water often looks flat at the rip, in contrast to the lines of breaking waves on either side of the rip. 2  A river of foam: the surface of the rip sometimes looks foamy, because the current is carrying foam from the surf out to open 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]. But some things that are still alive lead to the putrefaction, or decomposition, of the body -- we're talking about little organisms that live in the intestines.
This person was dead for over a week before being found. Notice how the skin is blackened. A great deal of liquid blood has poured from the lungs. This is the result of decomposition and appears on about the fourth day. This bloody purge probably gave rise to superstitions about vampires. About the fourth day post-mortem, the blood becomes liquified and gas builds up in the body due to bacterial decomposition. So in ancient times, when someone had died who was presumed to be a vampire, they would excavate the body and drive a wooden stake through the chest.