I think you should make the whole boat out of lead, and don't test it once until it is complete.
Then, when the day finally comes, walk to a nearby lake, with your boat on a trolley...
Throw it into the lake, with a smile of joy on your face, and watch as it slowly drifts off, towards the bottom of the lake, propellers spinning futilely in an attempt to move it.
...Or go with the styrofoam. I've seen a few RC type things made with that. Light, floats, and fairly strong/springy.
12/05/2008
Perth, since like, forever.