I am running a Helix 12 Mega DI G2N at the bow with link to an Ultrex. I have Lowrance HDS units at the console and am thinking about upgrading the console units. I will use 1 console unit for MEGA SI and sonar split screen and the other for chart. On occasion I put the sonar on 1 unit and the SI on the other while I am trolling side scanning. I know I need the Mega SI for the unit I will SI with, my question is to network all 3 units together and share info what should I use for the 2nd unit at the console? Does it also need to be Mega SI, or can it be any Helix 12? And can data be share between all 3 with 1 being G2N and the SI unit being G3N? Thanks for the help