Hel installing hummingbird 798ci

[crappie-little]

I have a Pro Craft V180 Not sure where to put this, I have IPilot with US2 and hooked to it I have a Garmin 120.
On the dash Lawrence X85. I am getting new humminbird 798ci hdsi. Where should I put the tranducer, should i put it
in the back of the boat and put it where i can see when im drivng the boat and turn it when fish in front , not
sure. Any help would be greatly appreciated. the garmin is old not very good,i could move the lawrence to trolling motor