Hey lynger1,
This looks really good and if it works will really piss off the paint manufacturers.
So you are saying that it has worked on your boat which looks like it is a Red Witch or Red Jacket or is it a Red Back??, which is about 20-25ft long, so I would assume you fitted the MS10-9M unit.
At $2,800 it seems like a lot of money to pay for what is pictured on their web page. The web page, in not terribly good English says, that the product has a 2 year warranty.
I guess that regular slipping and antifouling of my hull every 6 months (you can't buy antifouling paint with a good percentage of tin in it anymore) over a two year period would cost me $2,800.
If the unit fails after 2 years, I am back where I started and no better off financially. The price seems like a lot to pay for an ultrasonic transmitter.
I do not know much about electronics, but maybe if one of these units could be measured for what frequency signal it puts out, one might be able to go to Dick Smith's and buy the components and put one together for a few hundred dollars.
The concept sounds feasible enough to work but the price seems a little over the top. I would wear $1,000 or $1,500 and as we all know, boat owners are notorious overspenders on their foolhardy toys, me included.

Can you give us some more info lynger and possibly some photos? Cheers Cisco