A couple of days back there was a discussion about buoyancy of bodies in the water.
One thing which was not mentioned in this context (or at least I failed to notice it) was the fact that the authopsies mentioned that the cause of death was blunt force, no drowning.
This means that the lungs probably were not filled with water (at least not fully). The usual cases where bodies are in the water are those where people drowned. This makes a significant difference with regard to buoyancy.
This fact combined with the fact that it was in rather salty water makes me wonder if the bodies were really submerged in the first days. Personally, I doubt it for the reasons mentioned.