Keep a shammy cloth available on your boat at all times. Besides drying items, this material is excellent for plugging small holes in a boat bottom. This trick saved me and my boat on an icy duck hunt last year after an encounter with a rock at high speeds.
Another product you should have in your boat emergency kit is J-B Weld. Be sure to get the underwater type to ensure a successful hold. I have found it is better to apply this from the boat ramp if possible; however, in a pinch it can work out on the water. If you have both a shammy and some J-B Weld you can keep on fishing and enjoying your day. Please know that bigger holes can’t be fixed without professional assistance.