Transducer

[TroutSupport.com]

If you want to mount it in side the hull, you want to make sure its shooting through solid glass and not through glass/void/glass or some combination. Even delaminated glass won't give good result. It can not be a composite hull either.

Good info and thought process from above.

If you through hull mount it (through the glass) you can use any epoxy and bury the ducer halfway into a big ole' blob of it. If the glass is solid with no delamination it's as clear as the transom mount.