We take a look at what we need, how to store and more...
JUMP TO: HOW MUCH PER DAY / BRAIN FUNCTION AND ENERGY LEVELS / DEHYDRATION / OVER HYDRATION / CONSERVATION / WATER MAKERS / OTHER METHODS OF FRESH WATER PRODUCTION FOR SURVIVAL /
How much water do we really need?
There are other studies
showing that mild dehydration (1-3% of body weight) caused
by exercise or heat can negatively affect many other
aspects of brain function.
However, keep in mind that
just 1% of body weight is actually a fairly significant
amount. This happens primarily when you’re sweating a lot,
such as during exercise or high heat. Mild dehydration can also
negatively affect physical performance, leading to
Dehydration is one of the most common preventable medical conditions in the world. Yet for something so common, most of us are unaware of its dangers. Here are a few things you might not know about dehydration:
1. 75 Percent of Americans Are Chronically Dehydrated. A survey of 3,003 Americans found that 75 percent likely had a net fluid loss, resulting in chronic dehydration. Although the survey found that Americans drank about eight servings of hydrating beverages per day, this is offset by drinking caffeinated beverages and alcohol and eating a diet high in sodium.
2. Dehydration Causes Fatigue. A pair of recent studies found that young people who were mildly dehydrated were much more likely to feel fatigued during moderate exercise and even when sedentary. Unsurprisingly, fatigue is a common dehydration symptom, and it’s said to be the No. 1 cause of midday fatigue.
3. Thirst Means You’re Dehydrated. Dehydration triggers the body’s thirst response. So when you feel thirsty, dehydration is already setting in. In many experiments, just 1 to 2 percent dehydration has been shown to trigger thirst . This level of dehydration can happen quickly, especially following intense exercise or when battling viruses.
4. Dehydration Causes Foggy Memory, Irritability, and More. Dehydration, even mild dehydration, has been shown to put stress on our cognitive functioning. In younger adults, for instance, dehydration was linked to a dip in concentration and short-term memory, as well as an increase in feelings of anxiety and irritability. With children, studies are more conclusive that hydration can improve attention and memory.
5. Hydration Can Boost Your Metabolism. Although the evidence is limited, your metabolism could benefit from drinking cold water. In fact, one study found that drinking cold water helped boost healthy men and women’s metabolic rate by 30 percent. The researchers concluded that the body expended more energy heating the cold water, which resulted in the boost in metabolism.
All of the major systems of your body depend on water to work properly. Drinking adequate amounts of water helps your body:
- regulate temperature
- prevent constipation
- flush out waste products
- perform all major bodily functions
Most people, especially those who exercise in hot weather, are more concerned about not drinking enough water. However, drinking too much water can also be dangerous.
Over-hydration can lead to water intoxication. This occurs when the amount of salt and other electrolytes in your body become too diluted. is a condition in which sodium (salt) levels become dangerously low. This is the main concern of over-hydration.
If your electrolytes drop too low too quickly, it can be fatal. Death by over-hydration is rare, but it can happen.
Increased water intake
This occurs when you drink more water than your can remove in your urine. This can cause too much water to collect in your bloodstream.
This occurs when your body can’t get rid of water properly. Several medical conditions can cause your body to retain water.
Both of these types are dangerous because they throw off the balance between water and sodium in your blood.
What causes over-hydration?
Over-hydration is an imbalance of fluids. It happens when your body takes in or holds on to more fluid than your kidneys can remove.
Drinking too much water or not having a way to remove it can cause water levels to build up. This dilutes important substances in your blood. Endurance athletes, such as those who run marathons and triathlons, sometimes drink too much water before and during an event.
It’s also important to remember that water needs vary with age, sex, weather, activity level, and overall health. So there is no exact formula on how much to drink. Common situations such as extreme heat, significant activity, and illness with fever will all require more fluid intake than average.
In a healthy person, your urine is a good indicator of your hydration status. Pale yellow urine that looks like lemonade is a good goal. Darker urine means you need more water. Colorless urine means you are over-hydrated.
Some conditions and medicines cause overhydration by making your body hold on to more fluid. These include:
- non-steroidal anti-inflammatory drugs
Other conditions and drugs can cause increased water intake by making you extremely thirsty. These include:
- MDMA (commonly known as ecstasy)
- anti-psychotic drugs
Even with a water maker it is important to
conserve water on-board. From the obvious not letting
the tap run whilst brushing teeth or washing hands, to
collecting every drop that comes out of the sky.
Install a sea water tap. so long as you are in a clean anchorage, or on passage then use this for washing up, also washing hands etc, to rinse your dishes fill a spay bottle with water, or just a cup of water to rinse will normally do.
When in islands where water is an issue (particularly Cape Verde and the Canary Islands - don't worry about the Azores they have more than they know what to do with!), or usually comes from big desalination plants, be frugal, if in a marina, don't leave your hose running, try not to wash the boat too often, the locals will appreciate your efforts to conserve one of their precious resources.
There are many different ways to catch water, from a simple tarp to plugs for your gunwhale drain holes. Biminis make excellent water catchers - use an ordinary hose fitting in the lowest part of your bimini.
When it rains simply attach a hose to it and fill your tank(s) - yes it really is that simple.
If you have side curtains on your bimini, fold
up the edge to create a gutter, this can be drained directly
into tanks or other recepticles. O course any water
collected in your dinghy is perfect to use for washing or
rinsing clothes. If you are seriously low on water,
but not sure about its cleanliness, or you are out and
about, then think about getting a mini water filter straw.
If you're lucky enough to have one - great, if
not, this is a big investment, but worthwhile if you intend
upon long passages or being at anchor for any length of
There are many different makes, but Spectra really is the leader in this game. Their Ventura 200T "...is the same size and configuration as the Ventura 150, but uses a higher displacement Clark Pump to produce more water. This allows it to operate in warm waters above 50F (10C), delivering over 8 gallons (31 liters) per hour. With it’s modular design, it’s an ideal system for installation in tight spaces whether you’re cruising, fishing, or racing. Simple analog controls and gauges display the feed water pressure and the product flow meter. A hand-held salinity monitor and a three-way valve for product water testing are included." Spectra make many different models, also hand water makers which are perfect for lefe rafts and grab bags, click here for their website. (This is an independent review of spectra water makers - after 13 years of ownership and no problems).
A couple of survival methods for making fresh water
Papaswamp lives on an island, here's their method of making drinking (potable) water.
And here are a few other ideas...
Slowly pour some salt water into the pot. Do
Watch the pot as the water condenses. When
boils, it becomes pure vapour, leaving behind anything
that was dissolved in it.
Should the worst happen...and you've found yourself marooned
Find the gas bottle from your life raft. Open it and fill it with sea water.
Build a bank of sand and bury the hose. This will keep the hose steady as fresh water travels through it.
Make a fire and place the gas bottle directly above the flame. This will boil the salt water in the bottle.