Autopilot kit for sale. Only $350, some assembly required. Jack Edwards, a mechanical, engineer, loom builder (yes as in weaving), and many other things in his professional career has built a functioning Ardunio based sail boat auto pilot system. The little Ardunios have piloted his aptly named boat the Wile E. Coyote over 400 miles this summer using both heading, and GPS track mode with cross track error correction. There are some chores left to complete such as wind instrument integration, but it's an impressive success with such a tiny capital outlay.