Steve,



Frank Bethwaite says that the least resistant (to forward boat movement) angle of the rudder is when it is at around .75 to 1.0 degrees above or to windward of center.



On a boat with gybingn centerboards, then it should be .75 to 1.0 degrees higher or to windward of the angle of the centerboard.



He adds that this happens to be almost exactly the same degree of deflection that the water stream coming off of the side slipping center board is presenting upon the rudders.



GARY