they make bags for just this. there a double zipper camera like ziploc you can buy them on ebay for 10 bucks i think impur used a similar product in hawaii. i wouldnt use a ziploc, i looked into it but i wouldnt. being an adult here your better off using a clear non lubbed condom double knot anf seal the end with a silicon type adhesieve. this trick has been used by some photographers. it came from the military.