[George Z]

I found a post somewhere that showed how to do this. I took a piece of 2" PVC pipe, sharpened the inside edge with a file and used it to punch out plugs from high density foam ( the kind computers come packed in). Don't use a hammer, just rotate the PVC pipe with your hand. I made a bunch in just a few minutes. Wet the plugs, compress them and work them into the scupper holes. They are absouloutly waterproof. You could then add the cord to pull them out, but I've found that I can push them out with my finger. The butt of my rod also works. They float, so you can paddle back to retreive them. Quick, inexpensive, almost unlimited supply.