I had to smile while reading this...
Ok, buddy, quit hyperventilating about less than a dozen half dollar size blisters willya? I highly doubt that they're serious, and even if they've burned a caustic ooze filled hole in the hull, they can be ground out. It doesn't mean you're going to need a haz-mat suit and a team of fiberglass geeks at hundreds per hour.
The boat is 17 yrs old. its going to have a few blisters. Unless they've gone off the deep end, peeled, barrier'ed and epoxied. I doubt that they have and I doubt that it was/is needed.
I can't warrant anything about this particular tub, but suffice it to say it'd be a rare bird if this caused a real big problem.
We are not primarily on earth to see through one another, but to see one another through
Some people are like slinkies: not really good for anything... but you can't help laughing when you push them down the stairs