How do I repair a crack in my fiberglass boat hull?

The lovely ice storm this year did a wonder to my '89 DynaTrak. The drain hole filled with ice, and despite the boat being covered, water got into it through a few holes in the cover. The boat had about 6 inches of water in it when I broke the ice out of the drain hole with a screwdriver. The ice pushed out the transom, and I now have about an 8-inch crack along the bottom edge of the transom. Is this a job for standard Marine-Tex epoxy (which I've used to patch scraps and knicks before) or do I need something else?