sailing with autopilot

Since the wind is almost gone,i decided to make a autopilot with elastics that does not need power to work(to mutch sun in my had again).
To tell you the true,it actualy works,the helm moves to compensate wen the waves push the boat and comes back to the same place,so we sail and sail with it all day long,the only thing i got to do is get more strenght on the elastic.
Take a look at the picture.