Which model??
Assuming you have a motor, it must have a transom, which means its easy to make a removable bracket for your tranducer. You get quite a few portabe fish-finders, which pretty much stay in their box, so your only problem would be a battery.
My buddy ran his off a rechargable battery he bought at 'Brights Electrical'. Small, weighs very little and is rechargable.
Hope that helps!!
Regards
miles