If you have a humminbird and don't mind spending the extra $79 to get it, I'd recommend getting the plastic thruogh hull transducer they make. It'll fit in most scupper holes and is threaded so you can tighten it down. I like being able to accurately read the water temperature, plus mounting your transducer using goop or epoxy inside your hull only works for a short time and comes loose. I had to do mine 5 different times last year, until I gave up and rigged up something near my rudder. I've got a new yak now and the through hull transducer works perfect.