Connor,
An arduino is OK but then it would need to send mavlink messages. That’s possible but there are easier companion computer to work with. For example if an RPI3 was used then the APSync image could be installed on it and that includes Dronekit which is a simple SDK that could be used by python scripts you write to control the vehicle.
Coincidentally though I started assembling my Thunder Tiger Challenger 800 sailboat last weekend. I think the first step of supporting sailboats is to get them working first in Manual mode where the user directly controls the rudder and mainsail. Then we’d move onto Acro mode (where the pilot controls the turn rate and desired speed). After these are done we can do the autonomous modes.
I have a lot on my plate but maybe I could put together the manual mode support soon-ish.
By the way, how does the arduino read in the wind vane info?