The ways of the sea

Our navigator realizes that there’s always more to learn.

At the request of a writer with no scientific or maritime background, our navigator and astronomer are collaborating on a description of navigation: how to direct a ship at sea.  We needn’t go into the motivation for it here, though we might describe it at another time.  At any rate, they are reviewing and writing up what they know.

Our navigator has a certain amount of experience in the art, several years straddling the introduction of the Global Positioning System (GPS) into general use.  He can fix his position using ranges and bearings when in sight of land, is probably too proud of his skill with a sextant in celestial navigation, and has sometimes used hyperbolic radio systems (LORAN for one; they have now all shut down, though there are suggestions to replace them).  These are the scientific methods and the basis of his chart plots.

But of course there is more to navigation than that, and ships crossed oceans before the scientific methods were known.  Observations and calculations of tide and current are still important; winds and waves are carefully observed, for weather reports if nothing else.  Even though our navigator has never heaved a lead-line, he has checked the echo sounder, and taken note of what the chart says about the bottom (rocky, sandy, mud, whatever) in case anchoring comes up.

Some years ago the entirely different system of the Polynesian navigators came to his attention.  They managed to people the Pacific islands without anything that we would recognize as navigational equipment, crossing thousands of miles of sea routinely and arriving at small, inconspicuous islands reliably.  The system, as we understand it, depends on winds and waves; stars (but not used the way we do); fish and birds as indicators of position; and in general, observations we would call unscientific.  It all seems a bit magical, and he would be inclined to dismiss it entirely except for one important fact: it worked.  And it works, for during the past couple of decades there has been a renewed interest in learning and developing the system.

None of us is quite ready to assimilate this quite different skill and set out in a canoe from Hawaii, say, headed to Easter Island (though others have done so).  But by chance our navigator stumbled upon a connection.

In his collection of charts is one a half-century old, a voyage planning chart of the North Atlantic.  It has an enormous amount of meteorological detail: winds, waves and weather, ice and currents, plus of course coastlines carefully plotted.  On the back, so as not to waste space, is a collection on advice on survival at sea (assuming one is forced to abandon ship).  One section gives clues to the location of land beyond the horizon.  A steady pattern of swells will be broken by the presence of an island, with a different look upwind, sideways and downwind.  Cloud patterns can show land, as can the flight of birds.  There’s not enough information to cross an ocean, but there is enough to show that sailors around the world were making similar observations and reaching similar conclusions.

As is noted on every chart in his collection: “The prudent mariner will not rely on any single aid to navigation.”