Odds are more than likely that you will never find yourself stranded on a desert island. Yet the scenario is one that engages the imagination of many. In case you ever find yourself in this situation, a supply of fresh water is critical to survival. Here are some ideas to set up a method to desalinate seawater if you ever find yourself stranded on a desert island.
Instructions
Setting Up a Still
1. Gather the materials you will need to create a desalination still. Assume that you still have the clothes on your back and perhaps a rubber raft or flotation device from the boat or airplane. You need a large piece of smooth, water-resistant material such as plastic and something to collect the fresh water in such as a cup, coconut shell or bowl fashioned from raw materials such as leaves. Finally, you need something weighty to hold down the plastic.
2. Find an area of beach to set up your desalination still. Choose a spot not affected directly by the tide so your still doesn't wash away. However, you want it close enough to the shore line so that you don't have to carry the seawater too far to fill your still.
3. Lay the plastic material out flat and trace a line around it in the sand. Set aside the plastic material and build a raised barrier out of the sand running along the outline.
4. Dig a 2-foot-deep ditch inside the barrier, forming a circle. Reserve some of the sand to make a pile in the middle of the circle.
5. Form a pile of sand in the middle of the circular ditch. This pile should be elevated above the bottom of the ditch and water in the ditch, but be significantly lower than the height of the barrier around the ditch. This pile of sand should be about half the height of the barrier around the trench.
6. Create a bowl-shaped divot in the middle of the elevated sand pile. Make the size suitable to whatever material you are using to collect water. This indentation is where the water collector will rest.
7. Line the divot with the watertight material you will use to collect the water. You can use waxy leaves or coconut shells, waterproof clothing or part of a rubber raft or flotation device.
Filling and Using the Still
8. Fill the ditch with seawater using whatever means of transporting water you have available to you on the island. You could also channel it in from a nearby tide pool.
9. Drape the piece of plastic material over the still. Weigh it down on the outside edges with rocks to hold it taut and in place. Be sure it has enough slack to droop down in the middle.
10. Weigh down the center of the plastic so that it hangs over the bowl-shaped divot in the top of the sand pile.
11. Wait for the desalinated seawater to collect in the bowl you have made. The heat of day will trap the evaporating seawater under the water resistant material. Then as the moisture condenses, the slope of the material pulls it down toward the middle. Depending on weather, size of still and other factors, this process could take a few hours or several days to collect enough water to use.
Tags: find yourself, plastic material, barrier around, bowl-shaped divot, collect water, desalination still