One way is to collect rain. Another way is to erect cone shaped metal objects on which water will condense at night and run into a container. There probably are more esoteric systems but this should get you sarted.
If you don't have any machines or modern day tecnology and you DO have a salty sea how will you get clean water?
WEll, wait for rain, and collect rainwater.
In Navy survival school, we learned how to collect dew.
How do you collect rain water
In a bucket. A tarp. Fruit jars. Sheets of plastic. It depends upon how much you want.
Anything from cans to sheets of tin or plastic.
a bucket 1/3 full of s.w. with a jar in the center place a tarp (or clear plastic)over the top with a rock in the middle to form an inverted cone to direct the condensate run to the center and then fall into the jar.
To collect rainwater, you can use various methods depending on the amount you want to collect. Here are a few ways:
1. Bucket: Simply place a bucket outside in an open area during rainfall. The bucket will catch the rainwater as it falls.
2. Tarp: Spread a large tarp on the ground and secure it firmly. The tarp will act as a collection surface, and you can position it at an angle so that the rainwater flows into a container placed at the lower end of the tarp.
3. Fruit jars: Set up fruit jars or any other small containers outside during rainfall. Make sure to position them in an area where rainwater will easily reach them.
4. Sheets of plastic: Similar to using a tarp, you can place large sheets of plastic in a sloping manner to direct rainwater into a container.
5. Cone-shaped metal objects: Erect cone-shaped metal objects vertically on the ground or any other surface. As the temperature cools at night, water vapor in the air will condense on the surface of the metal objects. The condensed water will then run down and collect in a container placed beneath the metal objects.
Remember, these are just a few methods to collect rainwater. You can be creative and use whatever materials you have available to collect rainwater effectively.