You could keep it as a standalone system and wire NMEA 0183 data from your TZT2 to you. It would only get digital data. (Like Lat/Lon, temp, SOG, COG etc) It would not be able to be on the network or see the radar/sounder picture. You might be better putting a TZT9 up there on the network or using a tablet connected by Wifi to your main TZT2.