Install the 9 transducer and network the 7 to the 9. Let us know if you need any help. Be sure and in your 7’s settings, to Turn sonar off in the setttings.
So, this is opposite what Humminbird said. I just tonight got them networked, I needed software upgrades.
But, this is what i thought would make sense. Would I get the most out of using two transducers on the back? And just sharing waypoints?