Easy fix
If it is truly a pin hole it can be fixed with epoxy or this great stuff called "Marine-tex" It is a 2 part mixture like epoxy and is easy to use. However, my suggestion is tht you find out how the leak developed. Is this new, or have you had the problem for a while? Did you just buy the boat? I suppose that over time and several hard groundings (or one sustained grounding in waves) the fiberglass could develop some small holes. I would be suspicious of the condition of the centerboard trunk. If I were you I would do some investagating to find the source first. Then look at how to not only repair the damage but solve the problem to keeep it form reoccuring.Good luck let me know how it goesArt <)))><