Exact thing happened to me last year. I towleled it dry as much as I could, did more drying with a hair dryer, strapped and taped it back to the forms, let it sit a while, making sure no rain got near it. Everything turned out OK in the end.

: Well... I've been working on my first build, a Njord, and
: everything was going well. I had the hull stripped and glassed
: on the outside, had flipped the boat and decided to remove the
: forms and glass the inside before doing the deck. Several hours
: of scraping later (the small Surform worked the best) I was
: close to having a smooth hull. Oh... I've been working outside,
: by the way, on the back uncovered porch, keeping the boat tarped
: when not working on it. I left the boat uncovered, though, while
: I ran to the store and, lo and behold, we had a freak severe
: thunderstorm that left over an inch of water in the unfinished
: hull.

: Now the hull has warped all out of shape, not only splaying out at
: the sides but bulging on the bottom, creating a concave shape on
: either side of the keel. I tried reinserting the forms and using
: duct tape to strap together but that's not strong enough. I'm
: sure when it dries it will retain the warped shape. I think the
: only way to save the hull might be to remount the forms to the
: external strongback, put the hull back on the forms and use
: several wood screws at each station to pull the hull back into
: shape, maybe rewetting it, if necessary. I made the hull black,
: with graphite, and plan to paint the deck so I should be able to
: fill the screw holes with thickened epoxy and paint over.

: Does this seem feasible, or are there other solutions? I hate to
: start over...