Doesn't Hobie use a glued on neoprene anti-slip panel along the tramp frame? Does that feel spongy or water-filled?
Remember those thin neoprene bikinis back in the 80's? They were pure rubber, very thin with no fabric backing. They never seemed to get soggy. In fact, they seemed pretty hot at the time! I doubt if what looked good then looks as good now. See attached.
Your my kind of scientist David.