Features November 1, 1998 Issue

Offshore Log: Keeping Water Clean

Even when you make your own water, there are still reasons to filter it before it comes out the faucet. We installed a General Ecology Seagull IV filter, an expensive solution, but worth it.

Clean, safe drinking water can be a scarce commodity once you leave the cruising waters of the U.S. Most cruising boats we have met in our first year of tropical cruising have some type of watermaker for serious long-term use, but choose to take advantage of the local water supply when dockside or anchored in polluted harbors.

All shore-sourced water supplies, either in the U.S. or overseas, contain particulate matter. This may be pipe scale, sand, small bits of grass or other types of sediment. While not necessarily harmful to you, sediment can play havoc with your boat’s plumbing. It can settle in the bottom of tanks, only to get stirred up during an offshore passage. It can wreak havoc with water pumps, destroy ceramic water fixture cartridges, and prevent the seating of rubber faucet washers.

We learned this the hard way when our Grohe faucets started leaking after two years. Fortunately, replacing the cartridges was easy—once we found them—but I became determined to reduce sediment in the entire water system.

Protecting Your Water Pump
It is critical that you have an in-line sediment strainer just upstream from your freshwater pressure pump. We use a Par Pumpgard filter, positioned to be easily accessible for routine checking and cleaning. This is a compact, small capacity stainless steel mesh strainer in a clear plastic housing— about $14 at any marine store.

A Simple Pre-Filter
From Jurgen Kok and Candace Reynolds of Nirvana, a well-equipped Baba 35 we met in Grenada, we got the idea of pre-filtering shore water before it even gets to the boat. On a trip back to the States, we picked up a cheap ($20) Omni filter housing at a Home Depot. It uses standard 9-1/2" filter elements, which are available worldwide. For a few dollars more, you can get a clear filter hosing that allows you to monitor the state of the filter element more easily.

The rest of our custom pre-filter system consists of two plastic hose nipples screwed into the filter housing, a pair of hose clamps, 4' of 3/4" reinforced PVC water hose, and a couple of plastic garden hose end fittings. We screw the filter inlet hose to the shoreside water bib, then couple our own water hose to the filter’s outlet.

Total cost of this handy gadget is about $35, including a couple of spare 30-micron sediment filter cartridges. Flow rate through the filter is about 4 gallons per minute, so it provides minimal increase in your watering time.

Serious Filtration
In the rest of the world, Americans are known by the not-very-flattering nickname, “septics,” due to our preoccupation with germs. We don’t mind the nickname at all. In fact, given the contamination of much of the world’s water, a preoccupation with cleanliness is a good idea.

All the drinking water aboard Calypso, even that which we make ourselves, goes through a General Ecology Seagull IV purification system. This expensive filtering system—list price is almost $400—will remove just about everything harmful from water, according to the manufacturer. Any water considered “bacteriologically acceptable for treatment” by the U.S. Public Health Service standards can be rendered save by the Seagull IV.

The components of the Seagull IV model X-IF—the most common version seen aboard boats—are a compact stainless steel filter housing with bulkhead mounting bracket, a nicely done sink-mounted faucet, plus the appropriate hookup hardware.

You also get one filter element, which is good for about a year. Spare filter elements are not cheap at about $60 each ($49.95 at discount).

We mounted the filter housing under the galley sink and plumbed the filter straight into the pressurized side of our freshwater system through a T fitting.

An in-line shutoff valve upstream of the filter makes it possible to change filter elements without shutting down and draining the water system.

Defender Industries is the only marine retailer we have seen that carries the Seagull IV at discount ($312.95), but the system can often be found on sale at fall and winter boat shows.

Are we a little obsessed about the cleanliness of our water?

Perhaps, but if you must have an obsession, this is a pretty harmless one.


Contacts- Defender Industries, 42 Great Neck Road, Waterford, CT 06385; 860/701-3400. General Ecology, 151 Sheree Blvd., Exton, PA 19341; 610/363-7900. ITT Jabsco (PAR), 1485 Dale Way, Costa Mesa, CA 92626; 714/545-8251.

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