With the stabalizer fins--as soon as they move, or the boat rolls, that changes the center of lateral resistance, and the boat will drift off course. Even locking the fins will not prevent this. With many long keel sailboats--and even some short fin and skeg rudder they will hold course some peroids of time. My current boats will hold the course for a number of minutes after the helm is released. Unfortunately it is the characteristic of the boat