We're going to hijack flight pack voltage on an aircraft system. Just read the roll angle from the gyro sensor (an MPU650 in a GY-521 board), convert that to a number between 0 and 1023, then output that via a D->A board to get a voltage. We really want a value between 0 and 9 volts, but may have to settle for less. We'll see.
Add an RC servo reader to the arduino, and then read the PWM values and spit them back out. Make sure you implement a failsafe option. Test this, and see if you can still sail.
Now we check the roll value, and let the sheets out when we get "to much" roll. Can we still sail?
