I don't know about you but I have never liked to drill any holes in my boat especially below the water. If I were you I would be looking and trying to find ways to mount transducer without making holes in the boat. I think they are thick plastic boards that they glue to the transom and then screw everything to them. Also seen where they use strong magnets to hold them but I would not trust them. My thoughts would be to try and find a 1/2" x 4"-6" piece of hard plastic as wide as your transom at the bottom of boat use some good marine glue or gorilla glue to boat then you can mount everything were and when you want too. You may want to use another transducer on the other side later I have a transducer on both sides in the back of the boat and one on my trolling motor. That is my 2 cents worth and it didn't cost you anything. Be safe and good luck fishing