I think you will find
That in that area, the hull thickness is from 1/4" to 1/2" thick. Please remember I am speaking of the 22-25' O'Day's with CB's. My guess is that is is still in that range. To be sure, drill a 1/8th" pilot hole to see what is there. Repairing a 1/8th" hole is much easier than a 2" hole in the hull.I think you can be confident that it will be about 3/8" think.Make sure you put it on a flat surface. If you try to put it on the centerline, you will not get it sealed properly.I think you are making a good choice in your placement. r.w.landau