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JIMinFL wrote:
My thinking is backward from yours, Chuck. I think of the gel coat as the
layer that is supposed to be waterproof. The laminate may or may not be
waterproof depending on how well the layers are saturated with resin. I'm
sure if you scrape the gelcoat off something like a BayRay or other mass
produced boat, you will have a leak.
JIMinFL

I don't always agree with David Pascoe on some issues, but I think he
has written one of the most informative and easily understood essays on
blisters and how they affect a boat.
If you check out the illustrations and explanation at this link, you
might amend your opinion about gelcoat preventing leaks in a fiberglass
hull


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

I read his essay and I don't think that I said anything that needs to be
amended.
Pascoe did say that both the gelcoat and roving/mat are porous. I don't know
if this is true of modern resins but the older boats made of polyester resin
were somewhat porous. But not to the point that you would notice significant
accumulation of sea water in the bilge. I had an old Reinell once that
leaked about 2 quarts a day. It wasn't coming from the engine room nor way
forward. It had to be coming from under the cabin sole. I cut an inspection
port into the sole and found a spot where water was oozing in drop by drop
right at the center of the keel. I didn't see any cracking so I decided to
leave it as is until haulout time. After removing several coats of bottom
paint I found that the gel coat had been worn off . Probably from repeated
beachings at one time. My fix for that was a few layers of cloth and epoxy.

I would not let any crack or gouge in gelcoat go unrepaired. Particularly
under the water line.