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Ways to Make Seawater Drinkable In An Emergency

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If you live near an ocean or any seawater, you have probably wondered at some point it would be useful in case of an emergency. Seawater is usually not drinkable as the amount of salt in it will only dehydrate you further. But with the right steps, you can make seawater drinkable! 

If you need to make seawater drinkable in an emergency, you can distill it to get the salt out. Distillation can happen through boiling water and collecting the water vapor, or by running it through a high-quality distiller.

To safely consume seawater, you must take out the salt first. Drinking a lot of salty seawater can lead to many health problems as it will dehydrate you and overwork your organs. 

Seawater can be made drinkable with things you probably already have in the house, or you can invest in and use it for a long time. 

Distilling Seawater Through Heating and Collecting Condensation 

The most common way to make seawater drinkable in an emergency is to boil it and collect the water vapor. You have to make sure though, that you collect the vapor through condensation and then only drink the collected water.

You cannot drink boiled seawater as it has not had any of the salt taken out of it. Salt dissolves and becomes a part of the water, so simple boiling is not enough.

Distilling the water will separate the heavier minerals, like salt, and the pure water will evaporate. To collect the water that evaporates, you will need to force it to condense on a lid or plastic and then run into a clean container. 

The process of actually doing it is a lot easier than it sounds, so if it’s been a while since you’ve studied the water cycle, don’t worry. Just follow the steps and you will have drinkable water in no time. 

Upside-Down Lid Method

YouTube video

You will need the following materials:

  • Stockpot 
  • Smaller metal cup or bowl
  • Lid with a handle that fits the pot well
  • Seawater
  • Stove/ campfire / heat source
  1. Pour the seawater into the pot. Fill the pot only about ⅓ – ½ full to allow room for a smaller container to fit in as well. 
  2. Carefully place the smaller bowl or cup in the middle of the pot. Be sure you do not get any seawater into the smaller container as this is where your freshwater will end up.
    • The smaller container should be lower than the top of your pot and no wider than a cereal bowl if you are using an average-size stockpot. 
    • Also, make sure your smaller container is either metal or glass. It needs to be heavy enough to stay on the bottom of the pot and hold its shape but also withstand the heat from the bottom as well as the boiling water.
    • Do not use plastic or even silicone as they will not hold up well.  Place the lid of the pot upside down on the pot. You want the handle to be pointing down into your pot. Make sure that the lid fits the pot pretty snug to prevent as much water vapor as possible from escaping. 
  3. Turn on the stove, or place your pot above your fire, and bring the water slowly up to a boil.
    • The boiling water will begin to condense on the lid and run down to the handle in the middle and drip into the smaller container. The salt will stay down in the bottom of the big pot, and the water in the small cup will be drinkable desalinated water. 
  4. Once you have enough water, or there is no water left in the larger pot, turn off the heat and let it all cool down. Once it is cool enough, carefully remove the small cup of water. Let the water cool completely before drinking. And you are done! 
  5. Repeat this process as many times as needed to get the amount of water you need. This method works well when you need small amounts of water for drinking or cooking. It is relatively fast and simple to put together. 

For larger amounts of water, the methods listed below will be able to get it done in bigger batches. 

Sunshine Method

Another method for making seawater drinkable in an emergency is similar to the first but uses the sun to heat the water. So keep in mind that this will only work in warmer temperatures while the sun is out. But if you have access to seawater, the temperature will likely be warm enough most of the year.  

Here is a video showing the same principles I am going to discuss below. He is doing it a bit different from a wilderness survival perspective. Below the video we will show you a great way to do this from your home, camp site or RV.

YouTube video

What you will need:

  • large container for water
  • Smaller container for clean water
  • Tight-fitting plastic sheet, plastic wrap
  • A small rock or another item about the same weight
  1. Place your large container outside in a place that the sun will hit most of the day. If you need to move your container with the sun, make sure it is small enough to move around.
    • Containers that work well are large bins, kiddie pools, or other containers that are large and not too deep. The larger the surface area of the seawater, the faster this will work.
  2. Fill your container about ½ full of seawater. 
  3. Place the small container in the middle of the bigger one. Make sure, again, to keep any seawater from getting inside. This container needs to be heavy enough to stay down in the water but can be made of any material really as it will not get too hot. 
  4. Take the plastic sheet and put it over the larger container. Then you will need to seal the edges as best you can. If you are using a smaller setup, you can use high-quality plastic wrap and seal it down on the edges.
    • Larger containers can be covered with a plastic sheet and tied down with bungee cords or even duct tape. 
    • You are going for whatever will hold the plastic taught across the top for the water to condense on. It needs to be as flat as you can get it so that you don’t lose any water.
  5. Once you have your containers ready to go, place your small rock or another item on top of the plastic, in the center over the smaller container.
    • Your rock or small item should be just heavy enough to create an angle in the plastic so that the water runs to the middle and will drop into the smaller container. It should not be too heavy as it will rip the plastic or pull the plastic away from the sides.
    • Depending on the size of your setup, you could use a rock, tennis ball, or kitchen utensils. 
  6. Now you wait. Depending on how hot it is outside, you could start seeing condensation within a few hours. 
  7. Keep an eye on how well your water is dripping into the smaller container. You can add more small rocks if needed to create more of an angle if the water is not running down the plastic towards the middle. 

The sun method works well if you need a lot of water and have a good amount of time to wait for it. This could also be used constantly to make seawater drinkable as it takes no upkeep and does not need to be watched. 

This method is much more time-consuming but does not take any effort once it is set up. The sun will heat the water and create condensation on the underside of the plastic.

Once you have the amount of water you need or the water is gone in the larger container, you can take the plastic off and remove the smaller container. Be careful as you do so, as it will have all your drinkable water inside. 

Machine Distillers

There are many options for electric water distillers such as this H2O Labs Stainless Steel Water Distiller. These range in price and water capacity so they can fit most budgets. Each distiller will also vary in output of distilled water per hour, so  look for a water distiller that will provide you the amount of water you need. 

Other things to consider are the power source as well as any cleaning or upkeep you will need to do on the machine. If you are out of power as well as water in an emergency, you will want a distiller that will work without being plugged in or have an alternate power source for your machine. 

More Things to Consider

Can I Use Seawater for Anything Other Than Drinking?

Seawater can be used for a number of things outside of consumption. The salt in seawater will ruin any food you try to cook with, but it can be used in cleaning and other household uses. 

Clothing and dishes can both be washed in seawater. Soap and other cleaning agents will react differently in seawater, so you will have to experiment to find something that works well. 

You can also bathe in seawater, but keep in mind that you will have salt on you when you are done. 

You can get rid of excess salt from dishes and after bathing by towel dyring thoroughly. 

Can I Put Seawater Through a Filter? 

Most filters can handle a small amount of salt that is found in tap water and other hard waters. Seawater has too much salt for your average filter to handle. The excess amount of salt can overwhelm your filters and ruin the system. 

What About a Reverse – Osmosis Filter? 

While these high-quality filters can get out more contaminants than average filters, they are still not suited for making seawater drinkable as they cannot get out the high levels of salt. 

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Hi! I’m David. For most of my life I have been interested in emergency preparedness. Over the many years things have changed a great deal. From freeze dried food, to LED lanterns, preparing for an emergency has never been easier. The continual research I have done over the years has become the basis for this website. Now it is one of the most trusted sources to learn about emergency preparedness.