As you can see I have two of the Parallax HB-25 Dc motor controllers now on my workbench. They are rated at 6 to 16 volts (DC) at 25 amps. That should be rugged enough. I figure I only need one for testing but I would like to run twin screws on the demo boat.

The controller is just over 1 ½ inches square and about the same in height. That makes them very small for the power they can handle.  What makes them so high capacity is the attached micro cooling fan under the component board. There is a machined heat sink between the fan and the controller chip. The heat sink is drilled with holes like Swiss cheese.

When I first saw these controllers probably a few years ago, my first thought was these were perfect for electric motor control on a model boat; actually large electric motors on a large model boat. Now I get to test my initial premise.

Electrics and water always has me concerned. It is very possible the boat may be operated in times of light rain. So one of my challenges is how to mount and protect these controllers from moisture. If it was easy, anyone could do it. Other than a complete sinking, it’s a matter of splash control.

Then I just need a hull that is unsinkable (Titanic?)

Trials will of course be run in calm waters but who knows what thrills may lay ahead when confidence and reliability allow the operating envelope to be expanded. Maybe build the first model icebreaker with a balsa wood hull.  Uh… no, that can wait.