Humminbird AS GPS HS N2K GPS Antenna [730029-1]AS GPS HS N2K GPS Antenna The AS GPS HS is a precision GPS receiver with a heading sensor that provides fast position fixes with an accuracy of 2. 5 meters. An internal compass also provides constant boat headings displayed on your Humminbird chart screen, even while sitting still. This heading sensor makes it easy to understand your boats direction in correlation to the GPS chart for precision boat control.