Balanced rudder design

Can anyone tell me what proportion of a balanced rudder is (typically) foreward of the rudder stock?

 

15% of total surface area. Brett

 

Balanced Rudder

Thanks very much for the reply. As a result of posting the query the site immeditely threw up some previous discussions on the subject, which essentially confirm your reply.
Regrds
Barry

 

I've been told 18% of chord length. I'm sure it depends upon the actual shape of the rudder if you want it truly optimized, but it seems these number are 'close enough' for most applications.

 

There is no hard and fast rule, as always it depends on the situation. Can you give a bit more info such as what type of boat is the rudder going on, sail or powewr? Is it a high performance boat or do you just want to reduce the helm forces? For a power boat where feel is not too important the 15 to 18% suggested would be ok, if for a sailboat then I would suggest less so that some feel is maintained in the helm, somewhere between 10 and 14% usually suffices.