[Gerry Zagorski]

Jimmy - 4200 should be good to seal up the hole in the hull and it might be the best place to mount the new ducer. The reason I say this is 2 fold:

1) If your old ducer was working fine and reading the bottom while at speed then it's in a good area of the hull. You don't want any cavication bubbles under the particular area of the hull when you are under way because your machine will loose the bottom.

2) It is not reccomended to use shoot through hull ducers with anything but a solid fiberglass hull. There are a lot of boats out there that have cored hulls and the shoot through ducers don't like that.

So, if you fill in that old ducer hole with a solid material, chances are the ducer will work there.