There is also a swing up variety of rudder.
I think the balance with this type of rudder is slightly better, but is
less suitable for boats that are on drying moorings.
Also, if you try to steer the boat in shallow water where the rudder
cannot go completely down (or has hit the bottom and kicked up) then there
is incredible weather helm on the tiller and the boat is extremely difficult
to steer.
For shallow water work a vertically lifting rudder is preferable as you
don't get weather helm.