ArduRover 4 basic boat setup problem

Can any one assist me to get past the servo output setup. I cant seem to get any response shown when rudder is selected in the function field. I’m trying to configure a twin engine motorboat using the pixhawk orange cube with here 3 gps. I’ve set the frame parameter to “boat”. Should I be using rudder at all. Any help would be greatly appreciated as I’m currently stuck.

If you only have two motors for propulsion and steering and no control surface, you have to select “throttle_left” and “throttle_right” for the outputs the motors are connected to.

I’m not sure if you already know but the orange cube doesn’t directly interface with ardupilot like a pixhawk 2.4.8 would, so you have to set it up, painless 360 has a whole tutorial on it. It could be part of your problem maybe.

there’s a few vids on youtube about ardupilot controlled boats, you might check those out too