How to Find Water on a Deserted Island
Original photo by Marek Okon on Unsplash.
Collect rainwater in whatever container is handy.
A bowl, plate, or helmet will work—so will a life raft and stretched clothing. In very dry environments, condensation forms on surfaces overnight. Use a tarp or other fabric—shaped as a bowl—to collect water.
Collect dew.
Tie rags or tufts of fine grass to your ankles and walk in grass or foliage at sunrise. The dew will gather on the material, which can then be wrung out into a container.
Head for the mountains.
An island that appears barren on the coast may have a green, mountainous interior, which is an indication of freshwater streams and creeks. Find these by following trails of vegetation. Do not waste too much energy hiking or moving long distances unless you are relatively certain you will find water (meaning that the lush greenery is not far away).
Catch fish.
The area around a fish’s eyes contains drinkable liquid, as do fish spines (except shark spines). Suck the eyes, and break the vertebra of the spine apart and suck the liquid from them. Fish flesh also contains drinkable water—but fish are high in protein, and protein digestion requires additional water, so you are better off squeezing raw fish in clothing or a tarp to extract water.
Look for bird droppings.
In arid climates, bird droppings around a crack in a rock may indicate a water source. (Birds often congregate around cracks where water collects.) Stuff a cloth into the crack, then wring it out into a container or your mouth.
Locate banana and plantain trees.
Cut down the tree, leaving a stump about one foot high. Scoop out the center of the stump, so the hollow is bowl shaped. The roots will continually refill the stump with water for about four days. The first three fillings will be bitter, but subsequent fillings will be less so. Cover the stump to keep out insects.
Be Aware
Seawater is generally not safe to drink; its high salt content can cause kidney failure. Moreover, two quarts of body fluid are required to rid the body of the waste in one quart of seawater. As a last resort, you can drink less than 32 ounces of seawater per day; while not healthy, it may keep you alive.
Rainwater collected in a container is generally safe to drink, provided the container is clean and the water does not stand; any standing water is capable of breeding bacteria.