Who is the go to guy for all things Humminbird? I have a 998c si on my console and a 958c di on my bow. What I would like to do is sell the 958 and put the 998c on the bow and buy a new Helix Mega 10 for the console. Will the Helix and the 998 link up? How would the si hook up for both?

The Helix Mega will not share mega with a non Gen2 unit or solix/onix. Will share mega with another G2 unit helix unit that is Ethernet capable. So the 998 will not receive the mega imaging. You will only be able to network 455/800 and the 83/200. Will not be able to network chirp to the 998

They will network. I have a 998C at the bow and a 1st gen helix 12 at the console. Takes two cables to link them. Mine used a AS EC QDE Ethernet Dongle and a AS EC 15 E Ethernet cable. The 15 is for 15 feet. This works great for sharing way points.

44 is correct in that they won't share images. Its nice to mark a way point at the console then fish it from the bow. Just make sure to turn off the sonar on the unit you are not using so they don't interfere with each other.

Thanks guys, I knew they wouldn't share the Mega image, just need to know if they would link together. Will the si I have on my boat now for the 998c si need to be replaced with one from the Mega unit.

You mean transducer? Then yes. Totally different transducer and bracket

Yea, that's what I meant. Thanks

One more thing, I know your original question was about networking SI but I haven't been able to confirm but maybe someone here can is the ability to share the di(455/800) from a helix mega to one of the xx8 units. The network chart says the helix mega will not network the Di to a (998 in your case) but only si. Just something you may want to consider

Yea, I'm about to dive into this deal, probably will have a ton of questions. I haven't decided yet for sure, might just keep the 958c di up front and sell the 998c si. Not sure I need the si at the bow.

Call me John. I have Mega 10 and 9 and a 898. They are all ethernet linked. They share data, waypoints and more.