The image and the ideas from previous reviews of this product imply it is suitable as a map case and is a really decent product. Although I havent actually used this yet so can't comment on its waterproofing abilities, the biggest one won't even fit a Kindle in properly, let alone a map. The sealing mechanism is basically the same as a ziplock bag, and you can find cheaper heavy duty ziplock bags on amazon, ie those by webtex. Delivery was OK, and as always heavily (to the point of overkill) packaged by amazon.