I am Andreas from Germany, and I also want to build a sailing boat autopilot.
So far I have build the tilt compensated compass using Arduino, MMA7260 analog accelerometer and HMC5843. You can see here how it compensates for tilt:
It is, however, sensitive to linear acceleration. That is why I want to integrate it with a gyro.
How far have you got in your project?
Which GPS parser do you intend to use?
The ones available for arduino I think, are mainly 2, tinyGPS and the code by Lamers from NL. But both cannor parse data on wind speed or wind direction, nor waypoint data. If you like, we can develop the code together.
Which display do you intend to use? See mine at my webpage. Problem here is the large code for my LCD.
Maybe a graphic LCD has less code. I have no experience with that.
I may be interested aswell in the accel-maganetometer I2C chip aswell. Why ship be FEDEX?
There is the US postoffice that has "small flat rate packages" tariff to Europe at 10$. And I was charged no customs this way. Why not use this way?
Pleas accept my "friends invitation".
Hoping to hear from you. Yo are welcome to e-mail me. Find my address on my website.