Jack and the big-ass RC Boat.

This was originally a scale-model of a boat Katrina's father built. Said man turned the above model into a RC boat.

It's about 1M from bow to stern, maximum breadth of about 30cm, and a draw of about 15cm. (all these are estimates, without having it in front of me)

Driven by two motors (one for each propellor), run off a small car/bike battery (adds some weight to it, but that's needed for stabilization)