I too have just installed a  fishfinder finally in my 160 and it isn't as pretty as the other installation but what I did want people to be informed about was the sealant I used. As you can see in the pic it is gray when it cures. What I used was a general purpose/fuel tank sealant I get from my work. Its used in the aviation industry and is great stuff. It dries as a flexible rubbery consistency and almost impossible to get air bubbles in. Oh yea, it dries in about 4hours as well. If anyone is interested I can get a limited quantity of this stuff as when the shelf life date runs out. We can't use it on aircraft but works great on everything else.  Let me know and I'll give you directions for how to use it if your interested. - Jason

http://i167.photobucket.com/albums/u160/crjamt/102_0357.jpg

http://i167.photobucket.com/albums/u160/crjamt/102_0358.jpg

Actually it worked great for the next couple of weeks I had the boat. Then I sold it to a coworker of mine. But....... It turns out he really wasn't interested in the fish finder so I bought it back from him. I just a few hours ago reinstalled it in my new boat with another batch of fuel tank sealant. It was easy to remove from the old boat and works great. So far it is superior in my mind.