Hi @Corrado_Steri,
Yes, inflight calibration of the compass is available in Rover/Boat. I think it is described here on the wiki and the procedure is you set COMPASS_LEARN to 3 and then drive the vehicle around mostly in circles. I’ve used this successfully on my mapping boat.
GPS-for-yaw as we call it is also available for boats although I haven’t tried it personally yet I’m pretty confident that it works because a number of users here on the Rover-4.1 forum including Kenny and Yuri Rage are using it all the time.
Loiter for omni thrusters and also using lateral thrusters for Auto missions should happen some time after we complete the SCurves for rover project. Of course Loiter works with omni thruster boats but they rotate like a regular boat which of course is unnecessary for these boats.