Mounting Transducer in Fiberglass boats 

Correct...as long as you fully encase the gap between the transducer and the hull with epoxy - sound waves from the transducer can't go through air gaps and WILL cause errors/no readings.

Thanks a lot I was thinking I would have to drill a hole maybe cut the wire and splice back together.

so my fish finder works... but the plastic piece that is attached to the transducer broke, so I cannot mount it to the boat.... Right now, I just put a zip tie around the transducer cable at the base of it and used another zip tie to intertwine with that to run it through the boat mounting tabs.... looks like crap. Does anyone know if I can cut my existing transducer off and just buy another one? If so, will any transducer work or will I have to find the specific manufacturer and model? My fish finder is old.... but is also still working, so I don't want to replace it... I just want to see if I can put a new transducer on it.