G'day Bill,
I took an each way bet and modified the rake to somewhere between the original and an elliptical surf rudder. Will bevawhile before I can comment on its effectiveness and I won,t have anything to compare it against as I expect that the hard chined boat will feel very different to what I am used to in a high performance ski.
The difference was dramatic when I fitted the 9" surf rudder to my ski. Some have commented that doing so will make a tippy craft even more tippy. I don't think tippy is the correct term. there is an increase in turning response that can throw you off balance until you get used to it but the boat isn't " tippier".
Hope to have a pax update before too long as our Summer Holidays are upon us.
Cheers
An interesting bit of info that I have picked up on the subject is that the Supermarine Spitfire has a wing much like an elliptical surf rudder.