Worth Its Salt

Your boat depends on sea water, and I don’t mean just for staying afloat. Besides engine and generator cooling, most cruising boats have at least one appliance, usually an air-conditioning unit, and sometimes more than one, that depends on sea water for cooling. Sportfishing boats add ice makers, too. Larger yachts have hydraulics to operate stabilizers, and oil needs cooling when the yacht is underway. In short, seawater plumbing is an important component on many boats, but one that’s often overlooked.

That is, until the air-conditioning system craps out on a hot summer day because its cooling-water flow is blocked by seagoing gunk—which always happens, of course, when the boat’s full to the gunwales with guests. Then even the most unenlightened skipper realizes the need to keep the water flowing. Who needs the in-laws dripping sweat all over the varnish? How often this sort of thing happens depends on where you boat: Up north, where the water’s