Waterproofing Your Map: Keep your maps dry and readable.

by Michael Hodgson

There is no fun in trying to navigate while clinging to a soggy map in a downpour. Right before your eyes, the route home begins to turn into a greenish-brown papier-mâché clump. Your only hope at this point is that your memory of the route doesn’t wash out like the map did.

Making a see-through, waterproof cover for your maps is an easy way to prevent soggy-map syndrome. All you need is a large, freezer-weight Ziploc bag and a few sections of sturdy, waterproof tape like duct or packing tape.

• Simply cut the tape into a strip long enough to completely adhere to one edge of the bag from top to bottom. Press one-half of the tape, lengthwise, onto the side edge of the bag, leaving the other half of the tape hanging over the edge.
• Now flip the bag over, fold the tape down on itself and the other side of the bag.
• Repeat each step twice more, once for the bottom and once for the remaining side.
• You now have a wonderful waterproof map container that is reinforced on three edges.

Several other ways to waterproof a map are:

• Covering it with clear contact paper-making the map waterproof but very stiff and there is no way to now write on the map with a pencil. You can, however, use an indelible ink marker to highlight your route or make notes. When done, it is possible to clean up the marks with a gauze pad soaked in rubbing alcohol.
• Paint on a product called “Stormproof” or other map waterproofing treatments by Aquaseal or Nikwax–available at most map and outdoor specialty stores. The clear chemical coating renders the map waterproof, flexible, and able to be written on.
• A coating of “Thompson Water Seal” or other brick and masonry sealant will make a map water-repellent, but not waterproof.