Patches do work. If you can place it with your hands, that makes it easy. Get an underwater patch kit. You can use a scrap piece of liner or the clear patch that usually comes with a kit. Goop one side of the patch and put it in place. Squish out any excess cement and hold it in place until it sticks. The cement that comes with the kits, at least the ones I've used, is usually pretty aggressive and will tend to curl the patch quickly so you have to place it quickly. Boxer #100 is a slow acting cement that won't curl the patch quickly, gives you more time to place it, but takes a longer time to bond. If you can't place it with your hands then there are still ways to do it. Let us know what happens.