Dave, Don't follow the plan of basilk or David of just putting a plug
in the hole.If the hull flexes and it pops out or you scrape a rock and
it pops out or it just pops out from water pressure, most likely you'll
sink with your bilge pump pumping. Both sides of the hole need to be
ground back in a taper and resin and glass fabric on both sides used to
seal the hole. Follow the directions on the site Jim C. supplied, the
third category, High Risk, example 8, and you will be doing it right.
If you know what you're doing and have the tools and materials you
could do it in an hour or two. Sam