Howard, I'd better clarify what I wrote:
... If the cracks are in the hull.....and not the deck, it would seem odd to have them show up inside, as I there is a liner inside....
You're correct - at least in my case I couldn't see the cracks inside. I could see the cracks outside, and evidence of persistent leakage inside (I say "persistent" because there were actual stains where the water ran down, not just trails like from one instance of leakage).
Leak marks are easily explained by any leak in the hull deck joint.....which may mean it's not the crack that is leaking.
Again, that's right. The leaks and the cracks might not have been related directly, although both might be indicative of a hull-deck joint that should be looked at closely.
Hard to understand how it might have gotten cracked all the way around. I can't imagine how you could do that if you wanted to. It would require something drastic like being lifted by the toerails, and/or dropped from a travel lift, or perhaps something fell on it....like a tree or a building. They don't do that on their own.
Are you sure this is not a simple gel coat stress crack outside and you are seeing the hull/deck/liner joint inside and leaks coming from the joint?
On the boat I'm speaking of, the cracks were all the way through the gelcoat (at least). I mean, unlike more superficial spidering, I could actually slip my fingernail all the way into them. They were scallop-shaped and under each fastener (not on every fastener on the boat though, but perhaps a dozen or so). I wondered if perhaps a PO had attempted to tighten the hull-deck fasteners to stanch the leaks, and if the tightening itself might have caused the cracking. I was never able to find out for sure though. I realize you were probably actually replying to the original poster, but it made me think I'd better clarify my post as well. --- Rachel Fatty Knees 7' #302 Former owner, M-17 #334 Former owner, M-15 #517