Though our planet is covered in water, only one half of 1 percent is drinkable! For example, people who live in coastal regions are surrounded by water but it does them no good because one of the quickest ways to die of dehydration is to drink salt water.There are ways to make that water potable, though, and science is finding even more ways. In order to turn salt water into drinking water, you need to desalinate it first.
That just means that you need to remove the salt. There are many methods for doing this but the most efficient and realistic way to do it at home in a survival situation is by using the distillation by evaporation method.via(survivopedia)
The glass bottle method of distillation is similar to the glass bowl method, but it has a few more advantages. For one thing, when the process is over you will already have the distilled water in a bottle and won’t have to worry about transferring it from a large bowl to a bottle.
The glass bottle method is not traditionally used, but some people find it more convenient using bottles rather than a glass bowl with the lid of a pot. Either method will work find because they both evaporate and condense the water, which is the basic idea behind distillation.