Ninety-seven percent of the water on this planet is salt-water. Of the remaining three percent, two-thirds of it is frozen, leaving us with only one percent that is drinkable. That one percent comprises all the water in all the lakes, rivers, aquifers and clouds. It’s a limited resource and one that’s very critical for survival.
Fortunately, those who live in coastal areas have a plentitude of water, nearly at their doorsteps. All they have to do is find a way that they can make that salt water usable, either for drinking or for other uses.
First of all, salt water isn’t dangerous to use, it’s only dangerous to drink. The salt concentration in our world’s oceans is 3.5%. That’s higher than the 0.9% in the human blood. Drinking salt water increases that salinity level to a dangerous point. Since there is more salt in the water, than there is in our bodies, water will leave our cells, crossing the cell membrane in an effort to reduce the salinity percentage in our blood. But that will dehydrate the cells, causing them to die.
Even with this, salt water on the outside of our bodies isn’t dangerous. People swim in the ocean all the time, without it causing them harm. About the only problem that can come from that is the salt water leaving behind salt and other things on your body when it evaporates. But that little problem can be eliminated by toweling off when you get out of the water.
So if we can swim in salt water, can we bathe in it too? Yes. We can also use it for washing clothes and general cleaning. We just need to be aware that the water will leave behind residue when it dries, if we don’t wipe the surface off.
But there are things we can’t use seawater for, like watering our vegetable gardens, cooking our food and of course drinking. For water used in those manners, we’ve got to remove the salt from the water. That means distilling the water.
There are three different ways that we can distill water:
- A still that sits over a fire, just as if we were trying to distill moonshine
- A solar still, which uses the sun’s power, converted to heat, to cause the water to evaporate, then collect the condensate
- Making a solar survival still in the sand, out of a piece of plastic, pulling water vapor out of the sand and collecting the water as it condensates
The key to using any of these methods to distill seawater for survival is that it takes a lot of time to distill water. You’ll have to be distilling water all day long, just to get enough. While that’s better than going without water, it’s going to be a lot of work.
One other option exists, if you can make it work. In addition to distilling seawater to get drinking water from it, we can also purify it by using reverse osmosis. The problem with this is that reverse osmosis requires a lot of water pressure. Since we’re talking a survival situation here, chances are pretty high that we won’t have the ability to use an electric pump to provide that pressure. So you’ll need a manual pump that you can drive by hand, to pressurize the water and force it through the RO unit.
While this may actually be more work, it will be much more efficient, taking much less time. it will also require the preparation of finding a pump and RO unit and putting them together so they can be used. Nevertheless, if you have the technical ability, it’ll be worth it.
Don’t forget about the value of the salt leftover from distilling water. Salt is necessary for survival and will become a valuable trade commodity for bartering with. Collect salt as you go and store it up for use in bartering later.