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Cruising: the Passing of Traditional Navigation

Celestial navigation is a lost art in the age of GPS

Celestial navigation is a lost art in the age of GPS

Technologies are adopted because they make some part of life easier, safer or more efficient. Socrates argued almost 2,400 years ago that the new technology of writing would displace teachers, memory and wisdom. Since then other technologies have often led to the loss of the human physical, intellectual or intuitive skills they replace. In recent years technology has evolved so quickly it is hard to recognize the changes it imposes on our innate, learned abilities, our talents and our very image of the world around us.

The rapid growth of GPS technology is probably the best example of this change. Drivers used to plan trips by studying maps and choosing a route. They now simply enter departure and arrival addresses in an electronic device and take directions from an automated voice while being largely unaware of their surroundings. In his recent book, Pinpoint: How GPS is Changing Technology, Culture and our Minds, Greg Milner notes that U.S. Park Rangers have coined the phrase, “death by GPS” to describe incidents of travelers blindly following GPS directions onto abandoned roads and becoming stranded in a dangerous and hostile wilderness. GPS has had an even greater impact on those who travel the waters of the world. While accepting the great advantages of this new technology, it might behoove us also to take note of what we may have lost.

For several thousand years humans have been refining ways of finding their way across open water to a desired landfall, whether it be a point on a massive continent or a minuscule island. After all, most don’t go to sea just to “go to sea,” but to get somewhere, even if it’s only back home. These methods have included the arcane observational skills and conceptual models of the Polynesian navigators; the mythic sunstones of the Vikings; and the mathematical and astronomical methods of 19th and 20th-century celestial navigators. All of these methods require varying degrees of skill, judgment, science and art, as well as being subject to variables that are beyond the navigator’s control. For a celestial navigator, a high tolerance for ambiguity is a useful personality trait. Marking a latitude and longitude on a chart and saying “we are here” is as much an act of faith as a certainty. GPS has changed all of that, for better, of course. But also, in some ways, for worse.

Traditional tools require good intuition and comfort with some uncertainty

Traditional tools require good intuition and comfort with some uncertainty

The goal of the celestial navigator is to obtain a “fix,” a point marked on a chart consisting of at least two, but preferably three or more, lines of position crossing in a pinpoint showing a vessel’s position on the earth. These lines are, in reality, arcs of distance from the point on the earth’s surface directly under the celestial body, at the second the sight was taken to the vessel’s position at that instant. The plotting of these lines involves extensive mathematical steps with the aid of published tables. Taking the necessary sights also involves a number of physical skills on the part of the navigator, due to the fact that the angle of a celestial body above the horizon is taken with the sextant. This represents a physical challenge because the navigator is standing on a highly unstable platform that may be rolling as much as 45 degrees side-to-side, while rising and falling and pitching forward and aft. An accurate sight demands that at the instant of measurement, the sextant must be perfectly perpendicular to the horizon and steady. This, in turn, means a navigator must develop a dancer’s balance and agility, and use his or her knees and hips to compensate for the vessel’s motion and keep the sextant stable.

The celestial navigator’s day at sea is filled with the process of taking sights and reducing them to lines of position. This process begins before dawn with morning star for an 0800 position, includes several morning sun sights to create a noon running fix and ends with evening star time for a 2000 fix. These sights may total 20 per day and include stars, planets, the moon and the sun. Each is subject to the uncertainty introduced by motion and timing. Usually, a navigator will take more than one sight of a body to be able to choose the one that “feels” best. In fact, intuition plays a larger part in the process than many would admit. When plotting the lines of position every navigator hopes to see them cross at an exact point. However, this is a relatively rare occurrence, though tremendously satisfying when it does happen. Usually, the lines cross in proximity to each other, creating a triangle rather than a point. The navigator must then make a judgment call as where exactly his or her vessel is located: in the middle of the triangle, or at one of its corners? This decision is an important one, as it may affect any number of other choices, such as course corrections that will have repercussions days hence.

Then there are those times nature makes observation impossible because of cloud cover or a hazy, unclear horizon, placing yet more demands on the navigator. In such cases, the navigator’s job is to perform the informed guesswork of ded (or dead) reckoning. A navigator with no other resources develops a sixth sense for the vessel’s motion over the ground from observation of the wind, waves and knowledge of ocean currents. He or she then uses this to estimate the vessel’s position. The accuracy of such guesswork is tested when a viable fix is finally obtained with a change in weather, or a predicted landfall is made.

Celestial navigation at sea is an emotionally rich experience. One becomes attuned to the precession of the celestial sphere as navigational stars are tracked day after day, and the sun is tracked almost hourly. The fact that you are plotting your position relative to a point on the earth’s surface to which you are tied by your relationship to a heavenly body, at the local time in Greenwich, England, is, in its way, awe-inspiring. You are truly a part of the clockwork of the universe. Tremendous anxiety can come from days of overcast skies, but great elation also comes from a “perfect” pinpoint fix, with the ultimate pride and satisfaction coming from making landfall as planned and predicted.

GPS, even in the form of a simple handheld model operated on AA batteries, completely changes the navigation picture. There is no longer any uncertainty or anxiety in overcast weather, no need to schedule activities, including sleep, around star times, no need to suffer the ambiguity of an imperfect fix. Perfect latitude and longitude can be obtained at any time simply by pressing a button and waiting a few seconds for the appropriate satellites to be acquired by the device and produce coordinates accurate to within feet. This is, of course, in many ways a wonderful thing. However, there is also no longer a reason for a navigator to take any pride in that same perfect fix. No need to study the stars and constellations and learn their movement through the heavens. No reason to appreciate the steadfastness of the sun or feel a part of the cosmos as a whole. Perhaps saddest of all, when a navigator becomes a screen reader, he or she also loses that status as kind of shaman in the eyes of the crew.

It is interesting to ponder how those technologies, developed to increase the ease of undertaking maritime adventures also remove the very elements of the experience that formerly formed such a large part of the adventure. All things considered, if I were to embark on an ocean passage as a navigator today, I would not leave the dock without a GPS. However, knowing the limitations of AA batteries and electricity in general in a wet, salty environment, I would also bring along my sextant, Nautical Almanac and star-finder. I would also take to heart Rudyard Kipling’s warning to an Arabic ship’s master, or Nakoda:

The new ship here is fitted according to the reported increase of knowledge among mankind. Namely, she is cumbered end to end, with bells and trumpets and clock and wires, it has been told to me, can call voices out of the air of the waters to con the ship while her crew sleep. But sleep thou lightly. It has not yet been told to me that the Sea has ceased to be the Sea.” 

October 2019



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