Hi,

I viewed a 1983 Vancouver 32 recently that had osmotic blistering
covering about 4 feet of the topsides below the teak cap rail on both
port & starboard aft quarters. There are no blisters or signs of
osmosis below the waterline.

I'm concerned as to what might be causing these blisters, there are no
visual clues. The deck joins the hull underneath the cap rail and
maybe moisture has entered here?

Has anyone seen anything similar before?

Thanks,
Peter