I have an 86 P19 as well and the decks are getting a little soft near the stern where the skipper tends to sit. I thought the decks were just glued down and really didn't do much for structure in the hulls because of subdecking--seems like they are just to make the boat water tight. Like the Nacras, the deck is just glued down. I thought about putting portholes in deck and then glassing in some supports for the deck where it flexes, but it doesn't seem necessary. Do we really need to fix the flexing???