Yes, the DUI instructions do say to do that from the inside, no arguement there, but from personal experience I have learned otherwise. I now do it from both sides, as I should have put in the initial post. The first time was with the installation of a relief zipper, the next couple of times with minor holes. I found that patching from the inside works OK, but the fabric manages to wick some of the moisutre up unless you seal the hole from the outside as well. As you can imagine, the facric is exposed to the water if this is not done, and all fabrics have a wicking potential, albeit small for some types. And it does not have to look terrible, or be a hazard. If you are slow and methodical, it can barely be noticed, Do not leave any frayed edges, keep the patch as small as possible, and use the appropriate amount of glue. Oh, and btw, this idea was given to me by the DUI rep after I contacted them about the wicking action of the material. But hey, anyone can do it their own way, don't matter to me. Thought i might try to help someone avoid the troubles I had.