Water, Water, Everywhere and Not a Drop to Drink

Water, as everyone knows, is absolutely essential to life. Articles say that anywhere from between 50 to 70 percent of the human body is made up of water (I guess the variable is how fat one is). And a person can go anywhere from between eight to fourteen days without any before they die, and fat people can actually go longer without it than can someone who is skinny and out of shape.

People on land, at least in developed countries, take clean, potable, accessable water for granted. And we’re lucky, millions of people don’t have the water we take for granted and tens of thousands worldwide die each year because they don’t have it. More children, worldwide, die from the lack of clean water than those who die from AIDS and malaria COMBINED. But this is about access to water aboard a boat.

When you’re tied up at a dock in a marina water is similar to what it was when you were living ashore. Turn a knob and the water flows. You just have to hook up a hose from the dock to your boat.

What happens after you’ve cast off? At first you will depend on the water stored in your boat’s tanks and what you have brought aboard in containers. After that you can either make your own water with a reverse osmosis watermaker which is 1)expensive to purchase 2) a hassle to maintian 3) probably going to break down at some point which brings us to the most accurate definition of “cruising” ever: “Cruising is repairing equipment with inadequate tools and access to parts in exotic locations.”

OR, you can do what people have been doing since the dawn of time: collect and store rain water.


Don’t get me wrong. Watermakers certainly have their niche, and there are valid reasons someone might want to invest in one.

  1. As an emergency water supply. What happens in the unlikely event that your tanks spring a leak or get contaminated? Neither ever happened to me in all my years of professional and pleasure boating. BUT, I did have one incident when an inexperienced deck hand topped off the fuel tanks with the water hose, not paying attention to which deck fill he was opening. It’s also possible that a water tank could be contaminated with undrinkable water and you aren’t able to purify it. A hand operated model may also be a good thousand dollar investment for a ditch bag for long-distance cruisers in case they have to take to their last-chance of survival raft and could well save their lives. But that group of boater is a tiny minority of people who own and use boats.
  2. Reduce weight. A gallon of fresh water weighs 8.34 lbs, so, with a topped-off 50 gallon water tank that means you’re lugging around an additional 417 pounds.
  3. Extended range of travel. You don’t have to plan your cruise around stops to replenish your water supply.
  4. Save money in foreign ports. Available potable water in many foreign ports is limited even to their own inhabitants and if you want to fill your tanks from their precious water reserves you’re going to have to pay for it just like you have to pay for filling your fuel tanks.
  5. Provide a safe water supply on board. In many parts of the world safe, potable water is unavailable. If you’re able to make your own you won’t ruin your adventure with parasite-related illness.

But all this comes with a hefty price tag. Checking the West Marine on-line catalog the watermakers they offer range from $1,999.00 to $6,887.00.

An alternative, if you’re handy, is to build your own. You need a high-pressure pump capable of at least 1,000 psi, 3,000 psi is better. Then you have to buy the membrane that filters the water, the wiring and tubing, etc., etc. A Google search of “build your own watermaker came up with 8,170 hits, so there’s a lot of information out there if you’re so inclined.

If you have a watermaker you also have to have a power supply to run it, either 12 or 24 volt dc power or 120 or 240 volt ac power. All this presents another problem. There is one site I saw that is supposed to be able to make up to 72 gallons of water by dragging a special unit with a propeller behind your boat while underway and can be adapted to hand operation if you have to ditch the sinking mother ship. I offer this URL because I think the concept is interesting:http://www.watermakers.ws/

Collecting Rainwater

Harvesting rainwater has been going on since man lived in caves and a time-honored method of filling the water tanks at sea. People living a shore-based life have had cisterns for the containment of rainwater worldwide and is currently enjoying a reviva ldue to the inherent quality of rainwater and an interest in reducing consumption of treated water.

Rainwater is valued for its purity and softness. It has a nearly neutral pH, and is free from disinfection by-products, salts, minerals, and other natural and man-made contaminants. Plants thrive under irrigation with stored rainwater.
Appliances last longer when free from the corrosive or scale effects of hard water. Users with potable systems prefer
the superior taste and cleansing properties of rainwater.

There is archeological evidence that the concept of harvesting rainwater in China may date back 6,000 years. Ruins of cisterns built as early as 2,000 BC for storing runoff from hillsides for agriculture and domestic purposes are still standing in Israel today.

One of the best things about rainwater is that it’s FREE, and a collection system can be very inexpensive to install on your boat. When I was cruising on Nancy Dawson I only brought water from shore on two occasions in my nine-month trip. The rest came from the sky.

The first time I collected water on board was in Belize heading north from Belize City to Ambergris Caye. The wind stopped and the water came down so hard and heavy that it cut visibility to less than a hundred yards. I’ve been in fog banks were I could see farther. After it had rained for about five minutes in a deluge that Noah never had to deal with I felt that whatever salt and dirt might be on the sails had been washed off I raised the topping lift a bit and the water ran off the goose neck. I put a cup down to collect a bit of water and tasted it and it was sweet and clean. It was raining so hard and fast that I filled five of the gallon jugs I had aboard in about 15 minutes.

A couple of weeks later I stopped for a day at Caye Chapel where I filled my main tank with their water and headed south towards Guatemala. I had been thinking about how I would capture more rain water since that first experience. Standing in the rain to get the water off the goose neck didn’t seem like a practical exercise and I needed some system that wouldn’t require me to either get soaking wet or to put on my foul weather gear.

The deck fill for my water tank was on the port side just forward of the cockpit. I built a small dam from the cabin towards the toe rail and from the toe rail inboard leaving about a three inch gap so water could run the whole length of the deck and out the scuppers aft. I fashioned  the dam out with epoxy stick, something no boat should ever leave the dock without having several on board. They are a two part putty, one part wrapped around the other. They’re about six inches long and an inch thick. You simply break off the amount you need and knead the two different colored parts together until it’s a single color and them mold it around whatever you want to build or repair. Besides building the dam I used it to stop a persist ant leak in a through-hull fitting and to repair a broken part on my windvane self-steering. If I hadn’t had the putty I would have had to hand steer for about a thousand miles. After the stuff hardens it can be tapped to accept machine screws and the stuff hardens under water, too.

Anyway, I built the dam so that each section had a small groove where I could insert a small piece of wood when I wanted to utilize the dam for water collection but would otherwise remain open. From then on when it would start raining I would wait for a while for the rain to wash off the deck, open the deck fill and insert the piece of wood to close the dam and the rain water would drain into my tank. It worked like a charm.

Here are several other solutions that can be used for collecting this nectar from the Gods:



All this, of course, is grist for the mill for when I build my shanty boat, and since I’ll be living on the hook most of the time it will be a requirement. How feasible is it in Bocas del Toro? Well, I did some research on rainfall in the area and this is what I found:

Rainfall in Bocas del Toro, Panama
Month Mean Total Rainfall Mean Total Rainfall Mean Number of
(mm) (Inches) Rain Days
January 123.9 4.88 16.6
February 266.1 10.48 14.6
March 83.8 3.30 14.8
April 369.1 14.53 15.2
May 178.3 7.02 16.7
June 259 10.2 17.9
July 420.1 16.54 20.9
August 440.7 17.35 18.4
September 311.2 12.25 15.8
October 150.5 5.93 16.4
November 291.7 11.48 17
December 563.6 22.19 20
Total 3,458 136.15
That’s 11.35 FEET of water a year
This information came from the World Weather Information Service
Climatological information is based on monthly averages for the 30-year period 1971-2000.
Mean number of rain days = Mean number of days with at least 0.1 mm of rain.

With almost eleven and a half feet or rain falling in the area every year I think keeping dry will be more of a problem than keeping the water tanks full.

“All the water that ever was, still is today.  All the water that evaporates today the same amount also falls. The tears we cry could be the same ones Jesus wept”..Unattributed

POST SCRIPT: Ken, a regular reader of my blog and who contributes welcomed comments left a comment on this post and referenced the discharge of gray and black water from boats. You can read my reply, but I couldn’t upload a photo in the comments section so here goes.

Ken, this is common in the Bocas del Toro area as well as in the San Blas archipelago, and it’s NOT a phone booth built out over the water.bocas-outhouse


Filed under boats, Floating Homes, Houseboat, Living off the grid, Shanty boat

3 responses to “Water, Water, Everywhere and Not a Drop to Drink

  1. Water is our most important resource – gotta float, gotta drink.

    Simple desalinators are pretty cheap; even WWII surplus. That way you can use ocean water. You can get a RO water purifier rig for about $600 that will do the shantyboat job. Simple camping style handpump purifiers work well and are cheap (under $100). But collecting rainwater is cheapest and easiest. I lived on Kwajalain Atoll, in the Pacific, and the primary water source for 3000 people was rainfall runoff. The runway and taxiway and streets and open spaces all moved rainwater to our large RO plant. It was said that 1″ of rain allowed everyone on island to have a bath for a month. It rains 8-10 ft a year there…

    Question: What will you do with your gray/black water? A marine composting toilet and a RO treatment for graywater return makes you USCG legal; what about down there?

  2. oldsalt1942

    Ken, I appreciate the fact that you read my blog and I especially appreciate the fact that you take time to submit comments. Thanks. Since the boat will NEVER be coming to the US I don’t care about USCG regs, and you’d really rather not know how blackwater is treated down there.

    I’m going to be honest here, Ken, I sort of have mixed feelings about dumping the processed results of last night’s dinner into the ocean. Here in Fort Lauderdale, especially in the Las Olas Isles area. there are regular out-cries about fecal coliform bacteria levels in the water and, of course, boaters are ALWAYS considered the culprits. No thought or responsibility is ever attached to sixty year old leaking sewage lines from the numerous apartment buildings or condos that are tapped into those sixty year old leaking sewage lines that leach into the surrounding waters. It’s always the BOATS that are the evil doers.

    The city required that everyone who rents dock space to live aboard boats in that area install pump-out facilities which then transfer the boat’s waste to guess what sixty year old leaking sewage lines?

    Swimming is prohibited in the ocean around here several times a year because the semi-treated waste pipes from the sewage treatment plants rupture contaminating the water around what are supposed to be some of the best beaches in the country. And the sewage plants simply discharge THEIR waste a half mile or so offshore where it will be swept away by the Gulf Stream to become the problem of municipalities and beaches to the north and no one seems to think there’s a whole lot wrong with that except a bunch of “tree huggers.” (Note: I’ve hugged a tree or two in my day myself.) And yet the Coast Guard and local law enforcement officials regularly board boats here and one of the things they check, if they’re installed, is to make sure you have a holding tank. But then again, if you go a couple of miles offshore it is perfectly legal to dump your fecal coliform collection overboard.

    Then, too, I have this thought when I dump a floater overboard. HOW BIG IS A BLUE WHALE’S TURD? In my entire LIFE will I EVER produce enough poop to equal just ONE blue whale turd? So, folks, chew on that thought for a while. And don’t forget, fecal coliform is essential in all mammals in order to digest what they eat.

  3. Love the pic of the “Tidal Toilet, Mark II”. We had them out in the Pacific, always set on the ocean side of the atoll so outgoing tide does the flush to deeeeep water instead of the lagoon.

    Glad you don’t mind me playing Devil’s Advocate and bringing up things that you & I automatically think of but Johnnny Wannbe wouldn’t consider! I *know* what you’re gonna do with the black bits