Wind the threaded hook out from the casting so that the tip of the rudder is moved foward [under the boat]. Whilst doing this, keep locking the rudder down to check that it is not hitting the hull. We used to file chunks out of the rudders to get them further under the hulls.

CORRECTION! thinking about it now, you may need to wind the threaded hook IN. either way, get the rudders under the hull.[its been a while since I mucked about with prindle rudders]

paul