Considering that decomposition seems to be half as fast in the water as it is on land, would a body be intact enough after just over 7 weeks in the water, to be still considered a body (as opposed to remains?), and to allow a determination of homicide to be made that quickly?
http://en.wikipedia.org/wiki/DecompositionA basic guide for the effect of environment on decomposition is given as Casper's Law (or Ratio): if all other factors are equal, then, when there is free access of air a body decomposes twice as fast than if immersed in water and eight times faster than if buried in earth. Ultimately, the rate of bacterial decomposition acting on the tissue will be depend upon the temperature of the surroundings. Colder temperatures decrease the rate of decomposition while warmer temperatures increase it.