[chumbucket]

I did the shoot through the hull method with the Grady that I had a few years ago. Worked out well. Depends on the size of your transducer. What I did was to cut a section of 4" PVC pipe that was cut at an angle to match the deadrise of the bilge but level across the top. I cleaned a spot in the bilge and epoxied the PVC pipe and let harden. Then I laid in a bed of silicone. Very important to try to get out as much or all of the air bubbles as possible. I then set the transducer into the silicone and poured more silicone around it just covering the body of the transducer. You just want to be sure to have the transducer pointing straight downward or you'll get false depth readings.
Easy job and works well. 8)