Spent some time tonight making me a portable fish finder. I had an older Humminbird XP4000 laying around. I also had two booster pac that wouldn't ever jump start one of my garden tractors. So I took one apart and used it's battery and brain. Made a crude carrier out of wood. I wanted it to be as small as I could get away with, so it would fit in my sled. The transducer is a transom mount, but I tied it up so it will hang level. I just need to come up with some sort of float. I would imagine I need one, since all of the ones made for ice have one. Now I just need about 6 or 7 more inches of ice! 
I have seen may setups like this in the past and the people who have them say they work well. I would not go with a float because with this finder it will move around and I don’t think it will give you an accurate reading. Also when I have seen them used in the past people will drill a hole next to the one they are using or in between the ones they are using. I would just put the transducer on a piece of pipe or a flat piece of metal and put that piece on a hinge. So you can flip it up when not using or you can flip it down when using. Also I would figure in that you are going to need to change the depths of your transducer according to the thickness of the ice. It looks nice and good luck this season
