Late in the summer of 2019, one of my neighbors in Ohio put some interesting looking boats out in the front of his yard. I learned these were tug-boat sand boxes that had the hollow space in the blow-molded plastic filled with expanding foam, and a sheet of plywood adhered to the bottom. Since they could now float, each was fitted with an outboard motor. I loved the idea, but these were well known around the islands and both were sold almost immediately. 

I recently purchased a kayak, and the logical path forward was to design a system myself. Due to the shape of a kayak, I determined the best form-factor propulsion system was that of a jet-ski motor.

I initially purchased an off-the-shelf motor controller with a rotary potentiometer attached but quickly found that the rated amperage was inaccurate—leading to the controller failing at just 25% capacity. I then switched to an Arduino-controlled motor driver, giving me more flexibility in programming and the ability to integrate all functions into one processor, including steering and reverse servos, when they are added. Currently, I use a linear potentiometer set 75% forward for fine control and 25% reverse to help clear debris from the intake guard, since the reverse bucket still uses forward thrust.

After over three years of brainstorming, designing, prototyping, and testing, the project is really starting to come together. The CAD is nearly finalized, and I’m just about ready to install the full prototype. The propulsion components have all been thoroughly validated, and through multiple iterations, most of the issues have been worked out. The next big step is to mount everything into the kayak body. Once that’s done, I’ll begin fitting the steering and reverse servos. Once complete, this will bring the project one step closer to being fully assembled and operational.