http://www.modelgasboats.com/resourc...tricks/tuning/
Refer to Glenn Cupit's article on rudder set up, RUDDER "CASTER", A LITTLE CAR TALK, BACK TO BOATS. Articles talk about rudder length and rudder lift. With many testing, I got the following conclusion on JetChopper30 set up:
Offset the rudder 55mm to the right. Pretty stable turn at full throttle. Rudder too close to the centre line has too much prop., keel lift, lower turn stability. In perfect situation, rudder lift just balance the prop., keel lift.
Happy rc boating,
Leo