Wind indicators also can be used to provide heading information to the autopilot. Most wind instrument systems nowadays can provide apparent-wind direction data in digital form, and most autopilots are capable of using this information in preference to the heading sensor when the boat is sailing on the wind and the autopilot is operating in the wind-vane mode. You simply set up the boat so the sails and the helm are balanced, tell the autopilot the relative wind angle you require, and the autopilot uses this as its heading. However, varying degrees of satisfaction are reported for this system. The complaint seems to be that frequent changes in wind strength and direction along with masthead gyrations require constant adjustment of the autopilot.