Some of the Clear pouches have a "ziplock" type closure...works great.
We get ours from a Sporting Goods store...(Academy Sports)...it is made by Magellan Sportswear, made to keep fishing licenses in, and mine has been "park-tested" on several trips...and many fishing trips from a kayak!
(The ones we bought at Disney keep breaking on the tab...so make sure what ya get is fairly durable.)