Balanced rudder design

[BarryG]

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

[swanncat]

15% of total surface area. Brett

[BarryG]

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

[kengrome]

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.

[diwebb]

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.