If the gender can't be determined it's been there more then a little while.I believe when a person drowns they sink.And then depending on temperature of the water and how fast the bacteria do their work a few days later or even a couple weeks it comes back up from gas created by the bacteria trapped inside of the body cavity.Then of course once the gas is released down it goes again for good. I wonder if this was in fresh water above Pleasant Mills or tidal below? Hardly a place deep enough to drown above 542.