No leaks at all. Sat in the lake at my dock for two weeks last summer and not a drop of water came in. The rubber is 1/2" thick. You can use the same screws that are there now. I have a rubber gasket left over that I made. I had 3 that I made up with the material I bought. Gave one away and used one on my ski. I have one left if you would like it. No charge. Fits perfect to the drain hole shape.
