The time has come that I can upgrade to Ultrex. My issue is i need a better understanding of the link and non link and bluetooth US2 stuff. Do i only need the link if i have Humminbird units that are capable of linking to the ultrex and using the built in Transducer? Do they all cone with the built in transducer? Or is it the US2 identifies that it has the built in ducer? And Bluetooth whats the advantages of having it. Also what unit would i need to be able to set a route for the ultrex to follow or do i have to have the ultrex linked to a humminbird for that. I run Garmin and Lowrance graphs. I know im clueless guys and prolly sound dumb but any help would be great. Alot of money to spend to not get what i want/need.