I have a 2006 Bavaria which, I believe, was fabricated with Vinyl Ester resin. From the Bavaria Website
"A layer of isophtal acid resin in combination with a powder bound matt of glasfiber avoids the diffusion of water and obviates damage by osmosis."
I routinely keep the boat in the water year round (except for Spring short haul). An epoxy 'tie-coat' was applied to the yacht on delivery (mostly so the bottom paint would stick). Is osmotic blistering still an issue or did the chemists solve this problem years ago.
PS: Extra points if you're a chemist or engineer.