You can share waypoints, accessories and all Sonar between HELIX 9 G2N and HELIX 10 G2N ...
*You will need an adapter cable for each HELIX ...
https://humminbird.johnsonoutdoors.c...-adapter-cable
*You will need an Ethernet cable long enough to reach between the 2 units ...
https://humminbird.johnsonoutdoors.c...letype%3A27016
Rickie