Mary,
There is one readily available. I just didn't want to say SuperCat. It is a wide rudder head fore and aft with the rudder through bolt in the middle of the rudder head casting. It supports the rudder well at all angles. There is a green rope for GO that pulls the rudder down and a red rope for STOP that pulls the rudder up. The tiller stays fixed at all times for easy steering. You don't have to put the tiller crossbar up over your head and try to steer while coming down the face of a wave at the same time. Call or write Tom Haberman at Aquarius-Sail.com. There are probably pictures of the rudder head system on a boat at the web site.
BTW, the Dotans rudder head does not support the rudder blade when the blade is in the up position. There is no rudder head supporting framework for the rudder blade aft of the rudder pivot pin. The Dotan rudder system is a deep water start rudder arrangement.
Bill