I can see from discussion that the bed liner must not be worth messing with for the most part but has anyone ever tried using a rubberized undercoating spray?

There are many different brands out there but the theme is the same. There main purpose is to help deaden sound. I don't have any leaks to deal with, that's not my intent. I am looking for something that might make the boat a little bit more quite. The best part is, is that a couple of cans of this stuff is pretty cheap.

So anyone tried anything like this?

Your big issue is going to be the heating and cooling of this stuff.  Most of it is dark in color which will make it hot.  Then you put the boat in the cool lake water.  I see this stuff peeling off pretty quick.  Why not put a small deck in the boat with some carpet.  Or put down a cusioned pad and carpet.  I would check the flooring section of the home improvment store before I sprayed anything in the boat that will be a pain to remove later.

Good Luck,

TomD

There may also be some adverse SMELL involved with a rubberized undercoating type spray coating when it gets hot in the sun. I'd also be concerned about it getting all soft and tacky/sticky:o(