In order to display true wind relative to ground you will need a WSO100, a GPS100, a SSC200, and a display capable of computing true wind relative to ground. The WSO100 measures the apparent wind while the GPS100 provides Speed Over Ground (SOG) and Course Over Ground (COG), the SSC200 provides heading, and the display computes and shows true wind relative to ground. Maretron's DSM200 or DSM250 dedicated NMEA 2000 displays or Maretron's N2KView PC software are capable of computing and displaying true wind relative to water.