T - Cavitation of the rudders can be caused by a couple of different things but it usually has to do with boat/sail trim. It was a "problem" on the 20 with the 1st gen rudders. If you had your weight in the wrong place or sails trimmed improperly, the rudders would cavitate. Get everything right and in the right place and there was no problem. Rudder cavitation was a great indicator that you were doing something wrong and needed to adjust some things on the boat.