I've been working with this guy to 'upgrade' his remote controlled fishing boat with some autonomy.https://www.youtube.com/user/gleno2008/videos?view=0&flow=grid
So far I've settled on traditional RC, which currently has a range of a few kilometers and can be boosted.
The Autonomy is through Ardupilot http://www.diydrones.com/notes/ArduPilot
which allows for 'return to base' out of the box.
Its early stages as I'm currently going through tutorials online on how to decode frsky PWM (Pulse Width Modulated radio signals) so that I can remotely sense if the line has been pulled and remotely wind/unwind the winch.