network questions with helix 12 g2n and g4n

so originally I was going to run a eithernet from my bow unit g4n to my console g4n. but I had nmea 2000 installed on my new boat and for some reason I there would be a separate connection on nmea. but seems like nmea goes into the eithernet spot? I will have a 2 12s at the console. a g4n I bought at black Friday and my g2n. both are mega side imaging but I bought a 2d transducer to put on the g2n.

I mainly wanted the 2 network so can share waypoints when side imaging. so I thought I would network the g2n at comle to bow g4n. then side imaging with new one and just save waypoints. but I was like wait you usually scroll over when you see something. so saving a waypoint won't be in same spot. unless I motor over to it on side imaging and then save it on g2n! seems like my only solution. so obviously I'm confused on all this networking stuff, nmea 2000 and need help. I need to see engine data for sure. what can I do to make things easier to achieve my goals? if I need a box what else do I need and how to hook it up? I currently have 3 dongles, 20 foot eithernet cord and nmea 2000 installed

Helix units older than G4N do not have a NMEA2000 port so to have NMEA2000 input you need to convert NMEA2000 to Ethernet using the Humminbird NMEA black box. It must be discontinued now as it is not shown on the Humminbird web site.

A G4N has a NMEA2000 port but needs the quick disconnect adapter (AS QD NMEA2000) for the connection.

Since you have the black box connected to the G2N and it uses the Ethernet port, to network the black box and network the displays so you can share waypoints, you need the Ethernet Switch (AS ETH 5PGL). Then the displays and black box would connect to that.

OR get the AS QD NMEA2000 and connect the NEMA2000 back bone to the G4N's NMEA2000 port, and connect the two displays via Ethernet cable.

The AS EC QDE Ethernet dongles connect to a Helix and then an Ethernet cable goes between them or to the Ethernet Switch. You would need an additional Ethernet cable using the Switch.

Should find your setup here: Humminbird Networking Diagrams - Humminbird

ok thanks Wayne. I don't have a black box yet. I'm mainly interested in networking the 2 g4n. and just looked up that the nmea 2000 can do that. I believe I just need another t section to add the nmea 2k backbone? then run eithernet cable to front? my dealer even asked if I wanted it ran to the bow. and at the time I was just thinking engine data lol.