Set up and read Ansar 4. Too gather the same amount of information for Set up before racing takes twice as long because you have to see both Best Lifts and Worst Headers on both tacks before you have Mean Wind direction and can set the compass. Same as left. Same as left. Automatic compensation , in keelboats, for the change of angle between tacks when wind strength increases, Ansar 4.
Resolution is about one degree.
Resolution above 10 deg. is 5 deg. - too much. The wind may shift 4.5 deg. Far too large, see left. Allowed in all classes. Some classes prohibits electronic compasses.