Pete, you're awesome.
That 'green sealant' is the syntactic resin they used to join hull with liner. It's a really bitchen two-part expanding glue. You might also be able to notice the stuff was used to join top half with hull - they glued with that stuff and then applied wet glass tape to the joint except in the area by the dash and glove box. At that point, there's no tape and you can see the glue bulging out of there. These boats are so well built.
Five bucks says the hull isn't much thicker at your paddlewheel location than anywhere else, and that killer thickness explains the weight of the boats ;-)
