A second shot at water

Water, we all need it!

Since my last post about water I have had some discussions with more experienced sailors on some of the different sailing and cruising forums. I realized that I was thinking about it all wrong.

I was thinking about how much water the two of us would need to survive, not how much we would require. One person asked if I was talking about potable water or water in general.

Although most people agreed on that my plan for the water tanks was inadequate, a select few said that it was very doable. If, one would use the water for cooking and drinking  only. The luxury of a shower was limited to a cold seawater shower at best. Most of the time wet-wipes were used. Don’t knock the freshening power of a wet-wipe and dishwashing sponge bath on a hot and sticky summer afternoon!

Anyway, I now have realized that a more overlaying plan is needed. And water conservation seems to be on everyone’s lips. Dual taps in the galley, one for freshwater and one for seawater, is almost a requirement rather than a bonus. People shared many conservation ideas, something that can be very important when the water supply is limited.

The best tip that I heard to really save water was to get a spray bottle to fill up with freshwater. Use this water for washing your hands. Also you can take seawater showers and then use the spray bottle to rinse with. Also a lot of people seem to be using rainwater collectors, either prefabricated or using the mainsail and boom to collect water.

Although opinions differ in the subject as to if it can be used as a dependable source, since one is at the mercy of nature. The general audience seems to think that it doesn’t hurt in any way, even if you can’t order rain at a specific time or day. Stories were told about collecting several gallons during regular atlantic squalls, while others said that rain collecting at sea was pointless. I guess that it is up to everybody to make their own decision about the matter, but we will give it a shot anyway. Every liter counts.

Many said that they wouldn’t think about circumnavigating the globe without a water maker. They are a major cost as they cost between $2000-$4500 USD for the electric ones.


So I am a bit sceptic as to if we can afford it. I have found several PowerSurvuvor-35 on ebay, both new and used. Even the used ones are at a decent price. They look dirt cheap before you realize that you need to buy a service kit anyway. Which replace all the membranes, but brings up the cost to about 60-75% of retail. Otherwise the Katadyn PowerSurvivor 40E is very popular and as are water makers from Spectra.

I realized the need for a water management plan. That is, how do we get water, how do we use it and what do we do with it after it has been used.

  • Water will be able to be replenished  via hose/spigot/bucket, via rainwater collection and finally with a water maker.
  • The galley and the head will have both freshwater and seawater taps. The toilet will flush with seawater. Since we will have a water heater, and I doubt it likes seawater, freshwater will be used. So the shower will be a mix of fresh and seawater.
  • Wastewater will go into a septic tank and grey water will be dealt with accordingly.

We cannot fit more than 3 tanks, and the water bags apparently have a tendency to fail fairly quickly due to chafing in the more turbulent blue water. So that seems to be out of the question. We don’t want 100L of water leaking out into the boat. Perhaps I can weld custom tanks that can utilize more space than the normal square tanks.

The goal anyway is to have at least three 100L tanks, and preferably more. One septic tank with a capacity of at least 50L. I do feel that this is not enough, but I have not been able to find any ones larger. Another 125L will be brought in jerrycans as a reserve.

The plumbing might turn out to be a bit tricky since I do want the water tanks to be independent of each other to avoid cross contamination. It will increase the cost of pumps and valves, but I think that it is wise. And having a secondary pump that can be put to use in a more important location is never wrong.

With this setup I feel that the water supply is in better shape. Enough water for two people for 100 days with extreme water conservation, limited to drinking only, or for 50 days with an ocassional shower using 50/50 seawater and potable water. We should be able to collect at least 5L per week and running the water maker for an hour or so once a week should extend our water supply to acceptable levels. In the end it depends on how much time we want to spend pumping the water maker. We could become self-reliant, but one step at a time. The water maker is manual, and should give a weekly workout too.


2 thoughts on “A second shot at water

    • I have worked as a certified welder so I would build them myself, and the installation will be fairly easy when we are rebuilding the interior of the boat. It would be the materials for a few hundred euros vs the cost of a new water maker for around 4000€.


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