If youre going to network the 9 you just need a ethernet cable. Many prefer the imagery of the LSS-1 over the LSS-2. I know I wont do the upgrade. You should be able to network any transducer you want.I love my Lowrance products I have a HDS8, HDS7, LSS-1, Point 1, LWX-1, Sonic Hub, Weather, Sirius and connected via Ethernet and NMEA.