Hi Gary,

My ancient Mozzie had vertical boards and when I made the change to the 10 degrees rake it made made an enormous difference. That little shift in the centre of lateral resitance appeared to reduce the weather helm significantly and allowed me to set the rudders up close to vertical. I also reduced the width at the same time so that may also have had some effect.

Mind you the aft edge of the centreboard case is not as far rearward as the modern Mozzie so that could account for some difference (3305 mm versus 3353 mm allowable)

Jeremy Pearse did some experimentation with "A" class centreboards without much success. Not sure if they were 9" wide but they just didn't have the same tracking ability as the 10" boards. I'm sure Jeremy could give you some clarification.

Regards,

Peter