You can build an ALL SOLAR remote controlled boat using solar attic fan parts.
Have you ever been to the lake to watch the guys with the Chris Craft or Sail Boats? They're sitting around talking 90% of the time. Why aren't they running their boats more? Because the batteries only last about 20 minutes. So, if they spend a few hours at the lake they really only running the boats a fraction of the time (I know because I built a Chris Craft). So, here's what I made so I can have my hands on a controller the entire time I'm there.
This boat has absolutley ZERO batteries.
You'll need to buy one of those up coming popular Solar Attic Fan kits. It comes with the solar panel and a fan. You won't need the aluminum fan blade or shroud but you'll use everything else. I got mine on ebay for under $100
You'll also need basic RC electronics such as a matched radio and receiver, ESC and a servo. These are all things the typical RC modeler and model store have on hand.
Step 1: Easy Build
I don't have pics of it going together but you can get the idea from the pics. I used aluminum flat stock for the side supports and 4" plastic pipe for the pontoons. I got some steel rod the same diameter as the shaft of the motor for the drive shaft and the propeller is a 2.5" from Dumas. Mount the motor with a U-clamp from the hardwar store and build a bushing to hold the shaft near the propeller.
Step 2: Wiring
I made the rudder out of the same aluminum flat stock and just bolted it to the servo horn. Nothing fancy there. I didnt even need to use any kind of voltage regulator. The solar panel puts out 19V max and most ESCs are made for higher voltage so its an easy wiring job. Hook the panel up to the ESC power, hook the motor up to the ESC Motor Out, plug in the connectors to the receiver and its done.
Step 3: Performance
It also makes a GREAT rescue boat. If someone flips over or stops working I can just putt out there and bring them back in.
Send me pics if you build a differnd style!