A couple years ago some vandals punched a knife through my tramp in several places leaving slashes an inch or two long. I found a product called Seam Grip by McNett. I just applied it on top of the rip and let it cure. I expected it to come right off the first time I left the beach but it didn't. It lasted two whole seasons before I went ahead and bought a new tramp. Great stuff! It is sold to repair tents and tarps and such. It did turn a little yellow though after two seasons in the sun.