Just a thought, but wouldn't real police work actually work better, this is interesting, and some observations about some folks anchoring habits from Karen and Jim...
The most recent Sail Magazine (May 2012) has a short article regarding an ultrasonic anti-fouling system "The Ultrasonic Verdict"... It's well worth reading if only to assure yourself that most folks telling you stuff does not work are simply idiots.
Listening to Jerry Jeff
So it goes...