2) an improvised tarp of some sort, like the 2-person AMK heat sheet (which is 5'x8') tied off at the corners with a
sheet bend. If you have the money consider a 1-man silnylon tarp or go whole hog with a
small cuben fiber tarp. Add 50 feet of
Kelty Triptease cord for 1 ounce. Weight: 4 to 8 ounces (depending on fabric and size).
Along these lines, I've started carrying an
All Weather Emergency Blanket that measures 5 x 7 ft. It is a reasonable weight (285g), is durable and has grommets in the corners so it can be used easily as a tarp. At $15 its an affordable way to cover this need.
One of the other things I like about this blanket is that it is truely reusable so it can be a regular part of my camping / backpacking gear too.
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Victory awaits him who has everything in order — luck, people call it. Defeat is certain for him who has neglected to take the necessary precautions in time; this is called bad luck. Roald Amundsen