Re: truhull transducer
I have always used the epoxy, but you must first put the boat in the water and place the transducer in the desired location by hand. Preferably as far to the rear and as close to centerline as you can get. You must put a little water in the hull to fill in the air pockets under the transducer to see if it will work properly where you put it. Once you find a good spot you must get back on the trailer, drain the hull, dry the area and epoxy the unit down. Allow for cure time before bouncing across the lake. But as previously stated, once it's glued...it's staying there forever! Be very sure it's in the right spot!
Hope this helps. Good luck.