Gortex is just the type of fabric. Then there is a chemical applied to it for water proofing. and according to what I've been told it should be applied about once or twice a year. I also applied it to my camo suit that I have for hunting. I for one can say if you have a rain suit thats not keeping out the water just gettin wet. Use this product, for 10 bucks it's worth trying. Unless of course if you want to spend 200 bucks for a new suit.