Australian High Performance Catamarans Rudder setup showing the lock down arm in the rudder stowed position. This is a glass fiber arm that can be flexed. Two pins locate the arm in holes along the tiller arm and pivot the rudder up or down. I set it so the arms had a fair amount of prebend when locked down, so as to minimize the force needed to pop the pin out the hole during an impact wit hthe blade. Worked extremely well...hit two large sunfish at speed with no damage (at least to the rudder ;-)