I'm thinking of buying an Eagle 320 portable finder for use on my boat and kayak.  I will use a suction cup for the kayak transducer, but for the boat I will have a seperate one.  

I have a finder on the dash with a tducer on the transom.   The Eagle will be on the bow.

Where do you like your tducer, bow or trolling motor and why/why not?

Open for other ideas.

If I only had one unit I would put it on the trolling motor.Its hard to guess where a certain object is if you are in the front and your transducer is somewhere else. You transducer only covers a small area at a  time so if you are in the front and its in the back, by the time you see it on your screen you have already passed over it.For example if you were to pull you boat up onto a steep drop off your trolling motor may be in 1 foot of water but you fishfinder may be showing 12ft. since its in the back of the boat.Remember that a shoot thru hull transducer cannot give accurate temp readings. I would highly recommend buying the trolling motor mount

Gambler, that was my thought too.  However, is it a pain in the *&% when dropping and raising the motor?  What do you know about interference it may pick up from a 23 yr old trolling motor?

I like the idea of having it right under me.

I dont think it would get any interference at all. If you buy the transducer mounting kit all you have to do is install the transducer and zip tie the cord to the trolling motor  and trolling motor controlls. I have never had any problem deploying my trolling motor. just make sure you only zip tie it to the parts of the shaft that move.