RE: converting fishfinder for ice fishing.
Here's my set-up. Sorry no pics.
Cheapest single tray tackle box from Kmart you can find. Yank out the tray. Drill one hole in the back for the power cord. Cut a vertical groove down one side of the bottom half for the transducer cord. A dremel works great for that. I used the same console bracket and hardware as on my boat to bolt the bracket to the top of the tool box. I also used a skimmer style transducer that oriented about perfect just hanging from the cord. The 12V rechargeable battery fits neatly inside. For transporting it takes some squeezing but I can get the sonar, cord, battery, and transducer all neatly in the box. It literally cost $10 for me b/c I already had the battery and I just swapped the bracket and transducer back and forth from the boat. The only problem is that it's not happy much below 20 F. The display gets very dim so I usually shut it down if it's too cold.