Whichever physical design you choose, you'll need to control the motors, and the BeagleBone Black can do this task. In this case, I chose fairly standard brushless DC motors, four Turnigy D2836 9 950KV Brushless Outrunner Motors available at hobbyking.com, and then fitted them with RC boat propellers, the Traxxas Propeller Left 4.0mm Villain EX TRA1584 available at rcplanet.com. These motors work just fine when underwater and are easy to control with radio-controlled Electronic Speed Controllers (ESC).
For this project, you'll need four brushless DC motors, and four ESC controllers. You'll need to make sure that the ESCs will be able to control the motors to go both forward and backwards. Here is an image of one such unit:
This particular unit is a Turnigy Trackstart 25A ESC, made normally for an RC car, and is available at many retail and online RC outlets. The connections on this unit are straightforward. The red and black wires...
