: The other thing I soaked under water for two weeks is blue building foam. I
: had always though of using it in the bow and stern for floation, but the
: consensus seem to be that it would water log. This doesn't seem to be true
: in my experiment. I weighed the soak foam this morning on gram scales
: along with an identical non soaked foam piece and they both weighed the
: same. So in my next boat I am going to use it as floatation.

John,
Just to back up what you've stated here, my father uses blue styrofoam insulation as floats for hoses & submersible pumps in the dugouts at the farm. They are in the water year-round, frozen into the ice in the winter & generally exposed to the elements. They seem to last indefinitely & I've never seen one sink. (though I think the muskrats chew on it & the ducks perch on it)
Bryan