I was with a friend who had a CHB 41boat surveyed in Hawaii, as part of pre-purchase. Surveyor said fore deck had significant moisture, probably as a result of incorrect bedding/installation of cleats, and anchor windlass. He stated that movement of the deck in the vicinity of the windlass was most likely due to plywood or balsa core deteriorated to a "mush". Surveyor pointed out the readings on the meter, and marked the worst areas with chalk.
Recommended solution was to remove hardware, remove top fiberglass, clean out all rotten/water damaged core, replace core, replace fiberglass.
Original teak deck had been removed, unsure whether it was glued or screwed, but due to absence of any visible, filled screw holes, assumed it was glued.
Anyway, obtained an estimate of repair, and negotiated a SUBSTANTIAL reduction (North of $20k, including several other spots of "water saturation" noted on fly bridge and side deck during the survey)
Don used the boat for about 8 months before he decided to tackle the foredeck. He was going to install a new windlass at the same time. I helped him remove the windlass . . . bone dry. Core had been cleaned out for some distance past where windlass mounted, solid fiberglass infill installed, then drilled and bedded down. We assumed that the core was destroyed outside of the area where the fiberglass had been placed. We ended up drilling about 12, 1" cores in foredeck, flybridge, and side deck, in areas where the surveyor pointed out significant water intrusion, and rotted core . . . never found any water, never found any sign of water intrusion, core was dry, well bonded to both layers of fiberglass, no issues whatsover . . . except 12 each, 1" holes now in his deck . . .
. We had drilled about half of them in locations where he was planning on installing equipment (like permanently installed chair on fly bridge), so they weren't a problem, just required digging out core for around 2" diameter, and filling with epoxy/glass before installing bolts, but the other holes required repairing. We never did find ANY sign of core damage or water intrusion. We had taken pics of the "chalk markings" during the survey, so we were sure that the areas we "sampled" were the "worst areas of damage" noted by the surveyor . . . who cost the Seller North of $20k . . . The minuscule flexing the surveyor noted we attributed to the removal of the teak decking without building up the fiberglass to compensate for the teak removal. We ended up building up an area about 3' long by 2' wide in the area where the windlass mounted, faring the edges down into the deck. Used 1/2" marine plywood, covered by 1/4" - 3/8" of bi directional matt and roving, did same, but smaller size buildups under cleats.
Don ran into the Seller about a year later, and just told him that the deck issues had been "addressed" . . . .
My faith in "Professional Surveyors" using "years of experience" with moisture meters has been pretty much destroyed . . . . YMMV
