The large Waterproof Mad Map Case from Madwater is an accessory you definitely want when you go on that fishing trip to the hinterlands. It's rated to handle a quick submersion so if you drop it in a puddle or stream and grab it quickly, your maps will remain dry.
The case is banded on all sides with nylon and features a double lock sealing system. For ease of use, there are swivel snap hooks with deluxe stainless steel closures on all the corners that permit you to attach the case to just about anything. Its capacity is two pages held side-by-side or an open map book or a quarter of a typical 1:24000 topographical quad map.