Hi David, Your local hardware store should have a tube of two part 5 minute epoxy. It would have two tubes: one the resin and the second the hardener. These tubes have pistons in the tubes with a solid part on top, so that when you press on the top, equal amounts of epoxy resin and hardener will be forced from the tubes. This epoxy material is clear in color, i.e., will be light blond in color when hardened. To add color to it you could try mixing in a bit of dry plaster, that would give you a slightly heavier consistency of the material, and probably a closer color match to the hull color. Remember, if you stand 50 feet away from the boat you'll never see the spot. Place a piece of masking tape over the hole on the inside of the boat to keep your epoxy putty from dripping down the inside hull wall. My approach would be to fill the hole just a bit, leaving space on the outside for another small filling to level out the material, after the first material has hardened. Also mask off the area around the hole on the outside with masking tape to contain any smears, drips, or other problems that may occur. Epoxy can be worked using a fine file, or with sandpaper to achieve a level surface. Connie M15 #400