That's too bad, Tomasz_K, that you haven't received any response, here. I also am very interested in using LibrePilot and Revo for autonomous waypoint boat control. I am building a salt-water airboat for underwater FPV filming. I assume that, for now, ArduBoat is my only choice.
Although I have spent many hours researching and getting excited about LibrePilot and the Revolution hardware platform, I just found out, by way of this forum, that ground vehicles in LibrePilot do not include watercraft. I know that it was silly of me not to check that out before wasting my time, but I just assumed...