Sunday, July 25, 2010

A matter of water

Water, indispensable to life, at least fresh water. The trillion of
gallons of sea water that surround us help us to float, yes, but that's
about it.
As for fresh water, which is not available in unlimited quantities, its
consumption has to be managed. Therefore measured, since if you can't
measure it, you can't manage it.
When I started preparing for this voyage, on the one hand I took the big
watermaker that was on the boat off the boat, because I am not yet
convinced of their usefulness on the long distance voyage. Then, I had a
simple mechanical online water meter installed at the outlet of the
water pump. This way, I know permanently, to the tenth of a gallon, how
much water we are using.. Everyday at noon, I tell the crew what is the
average consumption since the last time we filled up, how much water we
have on board and how many days this represents. Just providing that
information help everyone to adjust their usage of water in relation to
those numbers.
Water on a boat has different usages. First and foremost, to drink.
Everyone has different needs, but roughly around 2 quarts per day
average. Anyway, there can be no restriction of any kind on allowing
people to drink water as much as they feel like.
Then water is used for cooking. There, a number of things can be done to
optimize the use of fresh water. For pasta and rice and many items which
have to be cooked in water, I use half sea water and half fresh water.
The mixture would have a salt content of 17 grams per litre. The norm
being 15, you just have to put a little more fresh water than sea water.
Then some items can be cooked in sea water only, like boiled eggs or
potatoes. For items which are steamed, you can use sea water only. For
wahing the dishes, washing laundry and washing oneself (especially
showering), same principle : use sea water first and then fresh water
for the last rinse. This way, you can take a shower for less than 1 1/2
gallons. And never miss an opportunity is the water comes from the sky.
For laundry, it takes a little more water and we try and avoid washing
laundry at sea.
Then the good news is that on a boat, we use sea water to flush the
toilets, unlike in a regular house.
On Papy Jovial, the average consumption since we left Darwin almost a
month ago stands at 3.544 gallons per day for the two of us. We left
with 220 gallons between the storage tanks, one jerrican of 6 gallons
and a portable shower. This represents 62 days of consumption and shows
that we certainly would not need to make water even on the longest of
passages. However, we would have to load the boat with those 220 gallons
i.e. 1,800 pounds of water. Everytime you want to move weight, you have
to provide energy. Everyone knows that the heavier the boat, the slower
she will be or the more power she will require. Same as I hate to load
heavy and cumbersome books on board and would rather have ebooks and an
ebook reader, same for water, I would like to reduce the total weight
that the boat has to carry.
This is where the watermaker comes into play. Ideally, if there were 100
% reliable, one could leave port with only 4 or 5 gallons and then make
water as needed. This is what the ocean racers like in the Vendee Globe
challenge, for whom weight is the ultimate ennemy, do. But they have
assistance ready to come whenever they are if they were in a critical
The average cruiser knows that he can only rely on himself and therefore
is not ready to take that chance. As a result, not only he has a big
watermaker, heavy and requiring a lot of energy (electricity mostly),
but he also leaves port with full tanks !
I keep thinking of that dilemna, and I think that in the future I will
go for a compromise. Reduce the size of the water tank to a number that
would provide strict minimum for the duration of the longest passage,
and then have a water maker for the extras, like a fresh water shower. I
still have to find a water maker that would be reliable, light in weight
and producing no more than 40 or 50 gallons per day.
Hopefully, I will have found it before I start my next big trip.

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