A highly disabled (quadriplegic) person can fully control this kayak via a SIP & PUFF Switch!
My design is a stand-alone fixture consisting of a Deck Plate that can be fastened to ANY kayak. Off each end of the plate is a pontoon which rides above a fixed direction trolling motor. Each system has two pontoons and two trolling motors. There is no need for a rudder or any mechanism to steer the trolling motors, as turning is accomplished by varying the speed of one or the other trolling motors.
The Motor Control Program is entirely controlled by a single SIP&PUFF switch!
The on-board Arduino Duemilanove Microcontroller puts the Motor Driver into Serial Input Control Mode and accepts Sip&Puff Switch inputs from the Rider.
It then sends appropriate Serial Commands to the Motor Driver to operate the two Drive Motors.
Split-second (0.1 - 0.6 seconds) Sips and Puffs control Left and Right Turning, respectively, and slightly longer (0.6 - 2.5 seconds) Sips & Puffs control REV and FWD movement.
Even longer Sips and Puffs Stop the motors or command them equally to Full Speed. Steering is accomplished via differential motor speed.