If you have two G2N units you do not need to get SI/DI on both. I run an SI on the bow and a regular Sonar/GPS on the console. The bow, as long as it is powered on, will share the Si/DI with the console. Save yourself a few hundred bucks as you don’t need the same features on both. Also, and SI unit also does DI. If you don’t want to leave one unit on to have the SI/DI, then put that unit where you fish most often. For me, it’s at the bow. I then used the mega Y cable to run the US2 off my Ulterra and the mega ducer into the single transducer input on the bow SI unit. As long as I power on the bow, the console sees it and I can run SI/DI until I find a spot I want to fish, then I power down the console and fish from the bow. Hope that helps, and saves you a few bucks.