SEARCH THE BOAT GALLEY 
Do you need a rehydration drink? If you’re cruising in a hot locale — typically the tropics, but it could even be a trip down the ICW in summer — you may find yourself sweating more than when you lived ashore in air conditioning and losing precious electrolytes in the process.
How to Tell if You Need a Rehydration Drink
A bad bout of seasickness, traveler’s diarrhea, or food poisoning can also cause you to lose electrolytes. And once the problem begins, it tends to be self-perpetuating and can become serious unless you take action quickly.
The good news is that most of these problems can be prevented or self-treated with a rehydration drink. I’m not a doctor, and be sure to seek medical help for severe cases. And more than once, we needed to give our dog a rehydration drink as she coped with the heat as well.
Common signs that you’ve lost too many electrolytes include:
- Extreme fatigue (beyond normal for the activity)
- Muscle cramps
- Headache
Decreased or dark urination and decreased sweating are also common. In the tropics, the first thing that I’d usually notice was that I’d take a drink and almost immediately break into a sweat — an indication that I’d been dehydrated.
Commercial Rehydration Drinks
Gatorade and Pedialyte are the popularly known sports/rehydration drinks and are available in many places. Gatorade and similar sports drinks are popular as they have nice flavors (and a bunch of sugar). Both come pre-made, which has the disadvantage of taking up a lot of storage space
While Gatorade and sports drinks can be adequate before you have any major symptoms, the World Health Organization (WHO) states that they’re not adequate for truly rehydrating a sick person as they have too much sugar (which makes diarrhea worse) and too little sodium. Pedialyte states that it is formulated to meet medical guidelines.
Oral Rehydration Salts
In many countries, particularly where water-borne illnesses are more common, little packets of oral rehydration salts made to the WHO preferred formula are sold in almost every drugstore, usually quite cheaply. Most are designed to be mixed with one quart/liter of water, but occasionally other amounts — check the directions. Even if you don’t speak the local language well, the directions are usually accompanied by pictures showing how much it makes.
If you are seriously ill, these packets work well. Outside the US, they are usually flavored to some extent, although not like Gatorade.
For “everyday” use before we had any serious symptoms, we mixed one packet with one packet of powdered Tang (also designed to make one quart) to make a half gallon of “Tang-o-rade.” It tasted pretty good and seemed to ward off any serious problems, depite us living in 90+ degree temperatures without air conditioning and going for desert hikes most days.
However, for some reason, these little packets are frightfully expensive in the US — even on Amazon. The Pedialyte powder is somewhat cheaper.
Diabetic-Friendly Rehydration Drink
If you are diabetic, all of the above solutions are problematic as they contain sugar. Since being diagnosed as diabetic, I use Hi-Lyte
Make Your Own Rehydration Drink
Rehydration Drink
Ingredients
- 1/2 teaspoon salt
- 6 teaspoons sugar (6 teaspoons is 2 tablespoons)
- 1 quart clean drinking water or 1 liter
Instructions
- Mix the ingredients until the sugar and salt are dissolved in the water. Any portion that’s not being consumed immediately should be kept in the refrigerator if possible.
- And if there is any question about the cleanliness of the water, boil it and let it cool before mixing the solution.
Notes
Keep this formula handy — you never know when you may need it and it’s nice as the ingredients are virtually always available.
Some links above (including all Amazon links) are affiliate links, meaning that I earn from qualifying purchases. Learn more.
Bruce Bibee says
It would seem like one could use (filtered?, boiled?) seawater for the salt content and just add the sugar – i.e. potable water + a bit of clean seawater + two tablespoons of sugar. We all get seawater into our digestive system when swimming and snorkeling so this doesn’t seem harmful. Seems to me that the ocean is the original electrolyte and should have everything one needs in about the right amounts.
Carolyn Shearlock says
Bruce, I know you’re a big fan of using salt water. I just can’t recommend it for drinking any large amount in places that most of us cruise. There is simply too much pollution in it, particularly a lot of petroleum (from boat exhaust) and fertilizer run off, etc. (our watermaker had a special prefilter to capture petroleum and we were quite surprised to see much it caught). These are very hard for the average boater to remove. While we ingest small quantities when swimming and it doesn’t hurt us, it’s a different story to drink a quart or two!
Miguel says
Bruce, sea water is a hypertonic sol. Most people stranded at sea who drink the sea water end up dead from severe dehydration due to masive diarrhea.
Bruce Bibee says
I was thinking of getting the seawater while out at sea. I did some quick research and here are the results if you want to check my math and keep it on file.
1 liter of seawater will weigh 1.027 kg. – containing 27g of dissolved salts. Or 4.2352 teaspoons – say 4.25 to keep things easier.
100ml will have 2.7g or ab out 3g, which is about a half teaspoon
1.0 tsp salt (regular NaCl) = 6.375 g or about 6g
If you are asking how much sodium is in a teaspoon of table salt, the estimation is 2400 milligrams. The recommended daily intake of sodium is 2500 milligrams for healthy adults. Just a side note: 6 grams of table salt is enough to kill you!
So one needs a one liter bottle and a 100ml bottle (perhaps a screw on cap like on a thermos). Start with one liter of potable water, pour 100ml into the cup and drink it, refill the cup with 100ml of clean seawater and pour it back into the bottle (the equivalent of one half teaspoon of salt), next add six teaspoons of sugar (two tablespoons). This will make a rehydration drink. One might also figure out how many hard candies make up the two tablespoons of sugar. For boaters one can put the hard candies and possibly the 100ml container into the one liter container – you now have a small kit for making rehydration drinks.
Craig says
Just don’t drink sea water. End of story. It’s nice that you pontificated over the numbers, but really drinking sea water is brain damaged.
Caron says
The WHO recommends that that if in doubt the salt and water should be no saltier than your tears. Which is the same as saline solution for cleaning/rehydrating eyes, nose ect.
That being said, I like cooking in saline solution made with high quality sea salt with a swish of kelp. Just watching them look for planes in the ocean gives me the heebeejeebees!
jpatti says
You really need to add potassium as well as sodium; if you only replace sodium, you may well end up with edema and/or leg cramps.
A cheap easy way to get potassium is to buy Lite Salt which is half sodium and half potassium.
I have often made my own sugar-free “gatorade” – basically Crystal Light (or similar product) with sea salt and lite salt.
If you really want to get fancy, add a pinch of one of the powdered calcium/magnesium supplements as well. The longer you are losing electrolytes, the more important it is to replace these.
Carolyn Shearlock says
That had always been my understanding — that potassium was needed as well. But the latest recommendation by the World Health Organization didn’t include potassium in the “recipe.” However, when I looked for the citation, I found that now they’re saying that ideally it might include some potassium . . . even though the “recipe” doesn’t include it.
The Rehydration Project — Recipes
Thanks for making me go back and check!
Andrea Dollins on Facebook says
Great info..especialy since I can’t stomach gatorade or any of those so called sports drinks..
John says
So called “rehydration” drinks are salted water, some potasium, and usually lots of glucose etc. “Gatorade” was originally developed expressly for University of Florida (The Gators) football players.
Humans sweating and doing physical effort in the hot sun use as much as 25 times more salt (at the extreme, depending on temp and physical effort and length of time) as the same person sitting in an airconditioned house. As a person sweats, they lose required salty body fluids. Those fluids can NOT be replaced with “just water” or fruit juice or any other liquid. The body requires a certain salt level in its blood. Not enough salt in the body, no liquids put back into the blood.
THE easiest way to replace required salt (and **some**, note “some” potasium) is to drink 6 oz cans of tomato juice. About the same salt/potasium as a quart of Gatorade and a tiny fraction of the calories (football players need calories, most of the rest of us don’t so much).
IF your body needs the salt, tomato juice/Gatorade tastes GREAT!! If it doesn’t, they don’t. If your body needs the salt and you don’t give it to your body, your muscles will cramp (a serious problem for endurance athletes, even in moderate or even cool temps) and you can even suffer heat stroke (your body stops sweating, your body temp raises and you can die). Lack of required salt is the reason when you are totally thirsty, you drink water and urinate almost as quickly as you drank the water. Your body can’t take in the water without the required salt.
Athletes will often make their own salted drink by adding salt a little bit at a time to half a glass of water, and keep adding until it tastes salty, then fill the glass with water and drink. Instant adjustment for the “right” amount of salt for the effort the athlete has made.
BTW, too much potasium is fatal. THAT is the reason the FDA severely limits the amount of potasium available in supppliments. Potasium poisoning is a genuine medical concern in anorexic patients who start to eat again.
Spring commissioning on my boat includes putting away a bunch of 6 oz cans of tomato juice for the coming hot weather. I drink how much ever tomato juice “feels right” and then glug glug glug two liter bottles of diet soda or water. At the end of the sailing day, I feel as good as when I started.
Sue Norris says
Great article for easy to understand info about the relationship between fluid loss and rehydration. When we get cramps from exertion ans sweating too much we use magnesium powder. My husband has to be careful about the amount of potassium he ingests.
In Indonesia they have a great isotonic drink on all shop shelves called POCARI SWEAT. It is very palatable and affordable for everyone. It is very popular. It is very thirst quenching. In Malaysia there is a drink called 100 PLUS. This is similar to Pocari Sweat but slightly fizzy. Both are great when out and about in SE Asia.
judith adams says
Yes on pocari sweat.
Love Sail Social Network And Online Dating says
Lemonade and salted peanuts is another good way on a hot day.
The Cynical Sailor & His Salty Sidekick says
So true about the northern hemisphere. I feel like I need to drink cups of cocoa down in NZ just now to stay warm 🙂
The Boat Galley says
One of my favorite cold-weather recipes for you, then 🙂 https://theboatgalley.com/tuxedo-soup/
ROBERT NOVAKOVICH says
I think its safer and easier to simply buy the product since it ccan be bought in packets now.
Don’t you? Its not worth getting ill for a couple bucks.
MLOsborne says
We purchase Gatorade powder in a canister from the local grocery stores. Transfer to an airtight container. Boom! You’re done!
Val Arden says
So, Caroline, for a diabetic, do you agree with using 1 tsp of Lite Salt mixed into a glass of Crystal Light? Or what would you suggest from common cupboard stock? Thanks.
Carolyn Shearlock says
I use Hi-Lyte Rehydration drops: https://amzn.to/2AM9c4r
They have ZERO sugar or any artificial sugars that can spike your blood sugar. The artificial sweeteners in Crystal Light will spike me, unfortunately.
Valarden says
If you did not have access to Amazon shipments, what recipe would you use, as a diabetic, from your stock cupboards, presuming Gatorade and Pedialyte were not onboard?
Carolyn Shearlock says
Ah, okay. I’d use 1 teaspoon of Lite Salt in a liter of water.
Valarden says
Thanks, Carolyn!
Dave Skolnick (S/V Auspicious) says
Whenever I think I disagree with Carolyn I go back to original sources. Usually her research pans out. In this case I disagree.
I think Carolyn is applying WHO guidance for serious rehydration to *maintaining* hydration. All the carbs and minerals in sports drinks and the mineral salts in the WHO guidance just aren’t applicable to people sitting around or exerting themselves lightly (sailing).
Drink water. Drink enough water so that when you urinate your urine is clear or close to clear.
Additives of any sort are really only helpful if they help you drink more water. Fizzy drinks are not hugely helpful. Just drink the water.
It is always a good idea to speak with your doctor. For niche issues like hydration doctors are as subject to “conventional wisdom” as anyone else. Peer-reviewed studies by scientists are your best source of information. The challenge is to read carefully to ensure you are applying the results properly. If you aren’t a marathon runner you don’t need to worry about electrolytes and other minerals. You need to be sufficiently hydrated to maintain an appetite and eat a healthy balance diet. If you don’t keep up and end up dehydrated (which means you didn’t drink enough water and didn’t eat a balanced diet) then you can expect all kinds of medical responses. Those response are not necessarily a good idea on a prophylactic basis.
I really hope David bounces back quickly. Push water.
Carolyn Shearlock says
Dave, I’m going to disagree with you. There are MANY medical conditions that can cause dehydration and electrolyte issues. If you live in a hot, humid climate with no air conditioning, you can definitely lose electrolytes as many doctors have told me. The trick is to learn the symptoms of simple dehydration, where you just need water, and the symptoms of electrolyte deficiency, where you need a rehydration drink. And in some places, drinking watered down rehydration drinks is the recommended way to keep things in balance.
Eric says
I wonder if people realise that water from a watermaker is almost totally demineralised and could easily be the cause of dehydration no matter how much of it one drinks.
My problem is how to properly re- mineralise RO water. Any thoughts?
Carolyn Shearlock says
That used to be a concern. But more recent tests say that’s not a problem. We use the Hi-Lyte drops to add magnesium, chloride, sodium, potassium and zinc. You can get it on Amazon — no flavor and no sugar. https://amzn.to/2sIrjnv
Eric says
Thanks. Do you know of a dosing system that can be installed between the watermaker and the tank?
Carolyn Shearlock says
No, but even if you are concerned with this, you only need to treat your drinking water, not what you use for dishes, showering and other washing up. We only treat the bottles of water we drink from.
Eric says
I’m sure that minerals such magnesium, for example, are more readily absorbed through the skin than in the digestive tract. So my wife and I feel that any water that comes into contact with our skin should, ideally, be remineralised – especially shower water.
We put a plug in our shower drain to make sure our feet get maximum exposure.
We also add magnesium to our skin cream.
sra says
This solution works wonders with a few squeezes of lime too especially if you are feeling a bit week. This also works great if having menstrual cramping.