I had a mouse get into my camping gear and do a number on, among other things, my tent. I needed something that would repair chew holes and make the tent watertight again. Enter the Kenyon repair tape. I found this inexpensive, easy to use, and it seems to form a nice tight seal. It hasn't been put through any kind of extreme weather yet, but it seems to be solidly attached and is made from basically the same material as the tent itself, so I have no reason to think it won't hold up just fine to water even in extreme conditions.