If you have a rudder system that only allows full up or full down, you can't steer with the full up, and you may break your rudders with the full down when you are going through surf in shallow water. So you need something that allows an in-between setting; right? So what rudder systems work best for going through surf?

I know the Hobie system probably works, since surf is what the Hobies were originally designed for. But what OTHER rudder systems work?