Heres an idea on what i did with my fish finder transducer. My transducer wire is running through a 12" piece of PVC pipe. Then i just slip it into the clips and im ready to go. If you dont want the clips, or to drill holes in the transom. Then you might just be able to hang the transducer over the side of the boat, sit it in the water, and tie the wire to your rope cleat. Or something along those lines.