Regardless if you connect the Ultrex or not if you are going to be adding 360 imaging you might as well get the HUB. just getting the cables will connect the 2 graphs but the 360 and the 360 mega both use a network connection as well, they are not like a regular transducer.
Each unit only has 1 port for network on them so you will have to use a network hub to add more than 2 devices.
Jody
No the MEGA 360 does NOT use a network connection. It uses the SI circuits in the unit's transducer plug. It can be shared via Ethernet network.