Steve nailed it pretty good
I have a "gooped" install in my tandem, been in there for 7 years, no problems so far.
I have it thru the scupper in my Trident 15, yes it makes the water drain slower for sure. I drilled the retaining nut and put better gaskets and straps on the rod pod to deal with big surf issues. Great way to go.

On my PA I went with the simple version of a wet mount.
I love it, the image is as good as in the water. I have dropped the transducer over the side to check.

The main benefit of this install is that the cables never come off of the back of the head unit.
Battery goes in a dry bag right next to the transducer, cables are run under the PA hatch. Piece of cake and never exposes those cable or head connections to water.

I made this out of some dense packing foam, and gooped it down, only takes a sponge full of water to get a great signal:
http://i239.photobucket.com/albums/f...ac/wetwell.jpg

running the unit out of box
 

with the default settings i am getting good signal . i can see jig underneath , but i was looking at a lot of surface clutter or junk in water column . is that normal ? plankton ? or is this due to the putty ? the arm has some very distinctive advantages . i ran the mad frog which probably is not as nice as the ram mount . using it with the 898 si transducer created way to much drag so i dumped it along with the 898 . 898 draws to much power to run 12 hrs. might not be an issue with a pro angler . :D . to much weight on my revo with me and a 12 pack.

I built a temporary setup similar to what Andy is using until I can buy the Pelican box and the Ram mount setup. It works, it's not pretty right now, but it will work until I get the other setup.

You don't need water around it at all. I have used the Duct seal install on 5 different FF and it's worked perfectly on each one. I even dropped my Kayak off the top of my SUV 2 times and the ducer never moved, wasn't too good to do to the kayak or Ducer, but they both lived.

Do you have your FF on max mode or clear mode? Max mode you will pick up more and it will look cluttered, set it on clear mode and you'll get better readings.
http://i26.photobucket.com/albums/c1...3/100_0265.jpg

Installed with Electrical Putty, surface clutter, but noting bad anywhere else. Again, if I wasn't using an si type FF I would always use the Putty installation.
It's clean, easy, and very cost effective.

Clear, easy and cost effective......these may not be the criteria some anglers are looking for.


I bet that there is at least one guy out there that wants .........great performance.


:D

I see your point, but I've never had one Fish Finder not show correct readings. I tested it with a guy who had his transducer in the water and mine in the hull, and the readings were exactly the same, including temp. Don't knock it until you've tried it.