Re: fish finder transponder set-up
I assume what you call the transponder is a transducer. Depending on the type of transducer you have, it can be in either location. It would help to know more about your fish finder and transducer to know where it can be mounted.
Where ever you mount, avoidance of air bubbles or water turbulance is critical. Inside the hull mounts usually utilize some type of material (ie glue or epoxy) to bond the transducer to the hull. If you do an in hull installation, for best results, play with the transducer location before deciding on a final mount. Modeling clay to secure the transducer to the hull can used for determining the best location.
Exterior hull transom mount, look for a location that is turbulance free, offers good water contact and is away from the motor. You may find you have to experiment with locations for best results.
Work is for people who don't know how to fish.