Had an issue with my G3 HDS12 not reading my Navionics Platinum card. I have G2 up front and they are connected with nmea. I remember reading a thread that they could share the map? My G2 picked up the card, but I could not find in settings where to be able to share it on the G3. I had some electronic spray cleaner in the truck and gave the card reader a quick hit with it, and it started reading the card again but wanted to know in case it ever happens again.