I will also be there Mon-Fri with 3-4 guys. I' can't wait!! Will be a good week for sure!!
You can't put a transducer "thru-hull" with aluminum... you have to put it on the outside of the boat. They do make suction cup mounts that work farely well depending on the smoothness of the surface of your transom. Usually you'll have to take it off for trailering or on plane. I would just screw it in with 1/2 inch long screws (pre-drilled) with a dab of silicone. It's hassle free and it won't leak. Eric