[McGillicuddy]

Marine-tex is commonly used for that. Comes in white, too. Or stick some tape on the bottom and fill the holes with some 5 min epoxy. If it has coring you might shoot some alcohol in the holes to dry the wood a bit... tapering the edge of holes a little with a conical or round grinding bit is a good idea for best adhesion and to keep the gel-coat from cracking but not really necessary for this purpose. JB Water Weld is a 2 part epoxy stick that you mix w/ finger tips and push in the hole sets in about 2 minutes - set it and forget it. I keep some of that in the toolbox and it sticks to anything. There, now you're on course to over think this one.