twin rudders

[petrel]

Ian,

Two rudders should theoretically work. But they will probably have more drag than a single rudder. The hole and cutaway in the transom will also have drag. For best saiing performance is not an ideal solution and may only be marginally better than your present set up.

In my opinion the best solution is being able to lift the motor clear of the water when it is not needed, having a smooth underwater hull profile, and one rudder. But his would ential you making a motor skeg like most other Telstars, fiberglassing over the hole under the transom, and using the existing rudder. But, frankly I think you would find the improvent in sailing performance be well worth the effort.

However if you have no recourse but to have the motor in a well. Instead of cutting away the transom have you considered mounting the motor on rails so it raises vertically and having a flap to cover the hole in the bottom like the Tom Cat 9.7 catamaran does.

http://www.tomcatboats.com/

Hope this helps
Geoffrey