Navio2 Rover with two traction motors

Hello I am new here and I am Portuguese , I am doing an academic project with a Navio2 board and I have some doubts that prevent me from moving forward. The project consists of an autonomous boat with two traction motors that are also the direction of the same . My doubt is in Rover mode can have these two engines to run on simultaneously or if I need a servomotor to the steering . It’s that I can put an engine running but the other does not work.

Thank you in advance and excuse my English bad .

Hi,

I think you should look at the skid steer option on ArduRover:
http://ardupilot.org/rover/docs/skid-steer-parameter-tuning.html

Thank you for your help.