|I have successfully mounted a regular depth sounder in-hull. There is some loss of sensitivity on an RL28 and less on an RL24 with its thinner hull, but preferable to another hole through the hull. As there is no damage done to the boat or transducer, it is worth trying with a fish finder as well.. |
I used PVC pipe just bigger in diameter than the transducer, cut so that when mounted vertically, it fits snuggly to the hull. Then glue it to the hull with epoxy and fibreglass tape. When dry, insert the transducer and fill with caster oil (obtainable from pharmacies).
You can also buy endcaps to fit the pipe and drill a hole just big enough for the cable. Drill another hole so that the air can escape while pushing the endcap over the pipe and later plug this hole with a self-tapping screw. It is not necseeary to screw the cap on.