To both the prepper and survivor the three real necessities are: water, food, & shelter…in that order. However, the order is reversed in inclement weather, during which survival is based on the Rule of 3: you can survive for 3 minutes without air, 3 hours without shelter, 3 days without water, or 3 weeks without food. When you go without food, you lose weight; when you are deprived of shelter (depending on the climate) you can get sunburned or freeze to death, but if your water supply is restricted...you quickly dehydrate and die. For survival purposes, a gallon per person per day is a good rule of thumb. It’s not realistic to assume you’ ll be able to carry enough freshwater with you on your bugout boat, so having a water-maker is a necessity.
Types of Water: White, Grey, Black
Whitewater is potable; greywater (sullage) is wastewater generated from domestic activities such as laundry, dishwashing, and bathing; blackwater (sewage) contains human waste. Whitewater is the goal today, but how do we make it?
Filtering vs. Desalination:
Filtering removes sediment, bacteria, pathogens, and some viruses while desalinization removes the salts, turning seawater into whitewater. Filters alone cannot remove dissolved salts. Desalinization requires a process known as reverse osmosis, in which seawater under high pressure (55 bar/800 psi) is forced through a filter (semi-permeable membrane) that traps the salts and allows potable freshwater to emerge. This desalinization process yields only about 20% freshwater; the remaining saltwater is discharged overboard as waste. The difference between filtration and reverse osmosis is the pressure under which the fluid is forced through the filter. The pump used to create the pressure head can be driven manually, electrically, or mechanically.
Equipment: Manual/12 V/110 v/Solar/Water-powered
The PUR-Katadyn Survivor 35, a hand-powered unit developed for and used by the military, is the obvious choice. The company’s first customer was the US Navy, who wanted a hand-operated, reverse osmosis water-maker for their 35-person life rafts. This compact unit can produce 1.2 gallons of potable freshwater an hour and need not be run continuously. At about $2,400 USD, this affordable, hand-powered water-maker is the least expensive unit aside from the DIY models.
12 Volt Systems:
PUR PowerSurvivor 40E. This compact, highly durable 12 volt water-maker is the smallest and least expensive power water-maker available. This unit delivers 1.5 gallons per hour and is the only power water-maker that converts to manual operation in emergencies. The power requirements are: 12 volts DC (draws 4 amps) or 24 volts DC (draws 3 amps). This unit has a list price of about $4,000.
Portable Generator Powered:
I like this portable water-maker, which is powered by a Honda EU2000i suitcase generator (my favorite) and can be operated as needed. The unit produces 20 or 30 gallons of fresh water per hour and charges your battery at the same time! My Honda generator gets about 8 hours of run time on a single gallon of gas, and I get about 200 gallons of freshwater for that gallon of gas! The manufacturer claims it’s the highest freshwater output water-maker per dollar. The replacement filters use Industry Standard DOW FilmTec RO membranes with a replacement cost of only $187 each. There is a lifetime warranty on all its stainless steel high-pressure fittings, RO pressure vessels, and its high-pressure pump, stainless steel head, and cast aluminum body. The units cost between $4,000-$5,000 exclusive of the $1,000 Honda generator.
Spectra Watermakers manufactures the finest quality, most efficient, quietest, and easiest-to-use water-makers in the world. If you have a sizable investment in your yacht, you will want equipment that works reliably when you need it. This equipment can be operated on either high or low voltage or from your engines when underway. If quality, rather than cost is the deciding factor, you may consider Spectra. They offer water-makers producing from 150 to 2800 gallons per day. In my novel Boca Chita, (www.bocachita.net) Mark uses a 600-gallon per day Spectra water-maker.
Solar powered water-makers use evaporation-condensation technology, in which salt water is heated by the sun under a transparent canopy and evaporates; the solar canopy captures the evaporated water vapor, which then condenses as “dew” and drips into a freshwater collector basin. This is nature’s technology; the sun heats the sea which releases water vapor which forms clouds; as the vapor cools within the cloud, it condenses as rain.
In 1952 the United States military developed a portable solar still for pilots stranded on the ocean, which uses an inflatable 24-inch plastic ball that floats on the ocean, with a flexible tube coming out the side. A separate plastic bag hangs from attachment points on the outer bag. Seawater is poured into the inner bag from an opening in the ball's neck. Freshwater is taken out using the side tube that leads to the bottom of the inflatable ball. On a sunny day 2.5 US quarts of freshwater could be produced. On an overcast day, 1.5 US quarts was produced. Similar seawater stills are included in some life raft survival kits.
Watercone Solar Still:
The Watercone is a mobile, lightweight, easy-to-use and portable one-person solar still that uses sunshine to transform seawater into purified drinking water. Intended for disaster relief in third-world countries, this simple, non-mechanical water-maker creates about 1.5 liters of freshwater per day. The parent company, Mage Water Management Company in Germany, http://www.mage-watermanagement.com/sal-meh/technology/ designs and builds large-scale desalinization water plants. I worked with them on a project here in Florida.
http://www.albin25.eu/our-a25ak-dido/34-dido-stories/60-didos-watermaker This DIY water-maker uses the high-pressure pump from an off-the-shelf Karcher pressure washer, which is available for less than $100! Lots of good links on this website!
http://www.sail-world.com/Cruising/DIY---The-Worlds-Cheapest-Watermaker./33568 The boat-owner designed and built this system, which costs about $2,000 and produces about 25 gallons of freshwater per hour. It’s a bit technical but still understandable.
I have not seen one of these water powered water-makers in use but I like the concept. The manufacturer claims that the Waterlog is the simplest and most rugged water-maker. This is the only self-powering, water-drive water-maker; you tow it behind your boat while you’re underway and like a taffrail log, a spinning propeller turns the pump. No electrics, plumbing, or installation for this simple water-maker. It is constructed entirely of stainless steel. The Waterlog 200 produces up to 24 gallons per day or 1 gallon per hour. Of course the downside is that it only produces water when the boat is underway. I don’t have a firm price on this unit, but estimated cost is about $3,000.
In a later installment I’ll discuss alternate power sources including wind-turbine generators, water-driven generators and the three generations of PV (photovoltaic): flat plate, thin-film and nanotechnology including the new PV paint!
Treasure Coast, Florida