Automatic steering gear which holds the boat at a constant angle to the Apparent wind. The vane senses the wind direction and actuates the tiller so as to correct any deviation from the pre-set relationship between boat’s head and wind direction. In some cases the vane acts directly on the tiller, in others it acts through a Servo rudder or tab. Both the latter are underwater surfaces which, when displaced to a small angle by the wind vane, apply the power of the water flow to the task of moving the tiller. There are many permutations of vane gear.