I am looking at a terrova 12v 55lbs thrust with us2. I will also be looking to add a fishfinder up front with it. I have Lowrance hdi-7 in the back now. Was looking to put and hdi/chirp unit up front but was wondering if the us2 transducer built in supports hdi or dual beam (2d and downscan) if someone could let me know I'd appreciate it. 

2D sonar only with the built in transducer. You can still mount your own transducer to the trolling motor if you want.

d**n, I guess 2d would be good enough 

Good description above...

...just curious, what size boat are you thinking about putting a 55 lb. thrust Terrova on?

I had one on Bass Tracker V-14...little boat...and I frequently was very low on power after a few hours on the water. Tried it with 2 batteries...helped a little....not enough.

A friend ignored advice to go to an 80 on a 16 ft. Alumacraft, hates the 55.

I had a 55 pound thrust Minn Kota motor on my 17ft Ranger for years. I could go 2 days on a charge and it moved me around OK. I've got an 80lb Terrova now, and it's obviously more powerfull, but I wasn't unhappy with the 12 volt.

Scott, you must have thinner water than we do... 

My trolling motor is on pretty much all day, at low speed.  The 55 couldn't handle that for all of one day, much less two.

I don't drift or anchor, so someone who used those tactics would get longer life from a charge.

Were it me, if it were a financial consideration, I'd go 55.  If not, no way.

Others will make different choices, and that's great...but to for me, most boats are underpowered with the trolling motors they have.