Some steps of improvement here.
Its still ice on my lake so I can not sail yet,
however I have set up the boat just like this car and yesterday I had a chance to test the car performance for some autonomous tasks like Return to base, Position hold and Waypoints.
It worked well over my expectations and clearly better than using Openpilot (last version 15.05.02, just going in circles).
Really encouraging results for putting the same configuration on to the sailboat.
For the car project, now I need some Lidars and functions to avoid obstacles