Harry Krause wrote:


BTW, no matter what anyone tells you or what you read, if you see
evidence of osmotic blistering on a boat you are thinking of buying,
move on. Those in the broker business will try to convince you it is
"only cosmetic," but it can have a far greater impact than that. I was
looking at a boat that had had some blistering repaired and noticed that
more pustules were breaking out elsewhere.


Please do tell how the typical gelcoat blisters found on most used
boats have a "far greater impact" than cosmetic.

David Pascoe, a surveyor who hates dealers and brokers as much as
anybody possibly could, has written that the idea the blisters damage
the structural integrity of a boat is a "misperception" and states that
after examining 4000 used boats with some degree of blistering he found
only about 10 where the blisters actually created an issue with
structural integrity. By my math, that's 0.25%- hardly the sort of
probability that should foster a rule of thumb "run away quickly if you
spot a blister". If a prospective buyer hires a decent surveyor and the
blisters are classified as "cosmetic", there would be no reason to pass
on a boat that was otherwise attractive. In fact, it's pretty common to
demand a further discount once blisters are discovered (most of the
time they are under the waterline and won't be seen until the survey
haulout), and then once the deal closes boat for many many years
without doing a darn thing about the unsightly but harmless pimples on
the bottom.

Pascoe's entire text on the subject:

http://www.yachtsurvey.com/BuyingBlisterBoat.htm


Please elaborate on your rule of thumb.