For strapping the transducer in place you could glue a couple pad eyes to the hull and use some bungies.

Bob

I tried scoring out a section of the rubber cup and the goo did not set like I had wanted it too...........thinking maybe I'm just going to set it in the bottom and add water......I've spent waay too much time on this already. The pad-eyes with goop is a good idea along with the tie downs. That should keep the transducer and well from moving around down there. I'm officially "over" the transducer stuff.....got a live bait tank to finish. My wife is about to strangle me at this point. Some good news though, did manage to get the Hobie off the garage floor, so now it's up to at least a height I can manage working on.

I hear you, I thought that I was the only one. :D

There are probably more of us than would care to admit..........