Try all you can to make it level, plumb and straight. Reason is because then the motor's thrust actually does the job of pulling the boat rather then wasting so much effort. And if you can, try to drop the trolling motor shaft dead center of the bow. That way there is zero effort to steer one sided. Either direction you want to go will pull the same. And that allows longer battery life from each charge. If you install it down one side, it will pull better one direct then the opposite direction. JMHO!