There's nothing like grabbing your rain parka when you need it and finding the zipper rusted shut. Trust me, I know because this very thing happened to me last season. I had to take a pliers, grab the zipper handle with all my might and yank that puppy back into place. Thanks to salt water and a little thing called oxidation, those little teeth had grabbed tight. Reeeeal tight.
I know there are things you can do to prevent metal zippers from rusting (a little WD-40 will do the trick), however we obviously did not do them. The next best thing to me is to avoid metal zippers and try to get gear with plastic ones. Unfortunately, most retailers don't seem to specify if their zippers are metal or plastic. I just recently got a new The North Face Women's Venture Rain Jacket (super cute, I got mine in yellow which is the easiest color to see at sea Scott has the men's version in blue) to replace my other one that rusted out and I can confirm it has lovely, unrustable, plastic zippers. Now does anyone know of a good dopp/toiletries kit with plastic zippers? Ours are tin roof rusted!