Here's the info on RCGroups on it http://www.rcgroups.com/forums/showpost.php?p=31547673&postcount=8116
"Just to make it clearer i was flying over land at a low height about 3 or 4 meters and I headed towards the sea where there is a sort of cliff edge or gradual slope really. As I went over the edge the phantom started descending. I tried to make it go up but it just kept descending!! Unfortunately at this point it was a couple of meters of the sea and went right in . Once in though it didnt stop - the blades kept spinning and then lifted out the water climbing to what I guess was about 20-30m (initially I said 50m but on reflection it was about 20-30m) It was still unresponsive but the return to home button worked and it landed. Cant believe it really!! I have the log files so I hope I can do something!"
You should post that his logs didn't report the same story

Things people need to remember. Visioning on VPS is off when GPS is locked, Only sonar is active. If the sonar receives to much BAD data it will give you this warning, land as soon as you can and do a reboot.. The VPS system had nothing to do with the above crash, more than likely pilot error.