In my first M17 I found that as long as I was able to fit the ob within the cutout I could always steer the boat with the rudder adequately. I have seen the telltale gouges of propellers hitting the rudder on a number of occasions. I know with my 17 when I used both to turn the boat it would practically spin on a dime. I had a long shaft Volve (back in 1983) and it easily cleared the water when I tilted it up into the cockpit. Tom B, Mont 17 #258