For all the precision of modern technology, sometimes there’s no substitute for the tried-and-true art of dead reckoning.
The certificate of inspection for a 1918 Silver Scale Vernier Sextant attests to the importance attached to the highest levels of accuracy expected from this vital (at the time) navigational tool.

The certificate of inspection for a 1918 Silver Scale Vernier Sextant attests to the importance attached to the highest levels of accuracy expected from this vital (at the time) navigational tool.

My first offshore race was the North Sea Race, a triangular course starting on the east coast of England and ending, with any luck, just outside the Dutch port of Rotterdam. All was going according to plan until, late in the evening before the start of the race, our navigator announced that he had left the charts back in London. Since it was too late to go back and fetch them, he set about making his own chart on the back of an old one, using nothing but a Reeds Almanac, parallel rules, dividers, and a #2 pencil. Intrigued, and just a bit apprehensive, I spent much of my off-watch time observing him methodically plot dead reckoning positions on the contourless “chart” and hit every mark of the course on the nose, including the finish line. I can’t say we sailed a great race—we were a green crew—but navigationally we nailed it.

If the art of navigation truly describes the creative process used by generations of mariners to move their boats from one location to another with a reasonable chance of actually arriving at the intended destination, or at least close to it, then I consider myself as something of an artist. A Rembrandt though, rather than a Picasso, in an era when universal access to GPS has all but eliminated the need for navigation in its artistic sense and replaced it with a simple follow-the-dots game, easily performed by most three-year-olds on a mobile device.

Helmsman2

Navigation, in and of itself, was a large part of what was most challenging and enjoyable about bluewater cruising back then, and stories of navigational haps and mishaps throughout maritime history are legend. At its core, dead reckoning was the name of the game with celestial fixes of one kind or another, weather permitting. Let’s be honest: nobody ever really knew exactly where they were with certainty before GPS came along. Dead reckoning was the navigator’s daily stock-in-trade, that and his ability to maintain a poker face when putting his finger on the chart and saying: “We’re here.”

 Chart, sextant, and pencil: simple tools of the trade used by mariners for centuries for a complex task

 Chart, sextant, and pencil: simple tools of the trade used by mariners for centuries for a complex task

I first met Okey in Lisbon, Portugal, where we were each provisioning our boats for an Atlantic crossing to the Caribbean. Okey had built a 32-foot sailboat in his home country of Denmark, following plans he had seen in a magazine, and had successfully navigated her to Portugal, staying close to shore most of the way. As our friendship developed, he confided in me his trepidation about navigating the 3,100-mile crossing to the Windward Islands, having never made a significant offshore passage before. Producing an inexpensive plastic sextant from a locker largely filled with foul-weather gear, he asked if I knew how it worked. He also produced a one-gallon wicker bottle of local rum, which he graciously insisted we should drink “because it was very cheap.” It tasted like jet fuel and delivered similar take-off power. Our sixth shot cut our training session short as Okey’s arithmetic became unstable and he could no longer add or subtract degrees, minutes, and seconds, a simple but necessary skill in calculating latitude from a sun angle. Two days later, our crew set out for Las Palmas, Canary Islands, bidding farewell and good luck to Okey, never expecting to see him again.

It’s a large ocean, and there are no sign posts along the way.

It’s a large ocean, and there are no sign posts along the way.

Two weeks later, sitting at anchor in Las Palmas, the unmistakable profile of Okey’s handmade sailboat hove into sight. The training sessions resumed. More jet fuel was consumed. One morning, Okey’s boat had left. I lifted my bloodshot eyes to the heavens and wished him well, once more, never expecting to see him again.

Several weeks later, no sooner had we dropped anchor in the crystalline water of Bequia than we recognized the frantic waves from a chap on a small 32-footer anchored nearby. Minutes later, our new friend Okey arrived on board with a smile as wide as the Caribbean and, of course, a fresh jug of jet fuel.

“Thanks for the lessons,” Okey gushed. “I only missed St. Vincent by 10 miles.”

His first landfall had been the Pitons of St. Lucia to the north and he was sailing directly between the two islands. Headed due west, his next landfall would have been Nicaragua, some 1,700 miles away. I like to think that his newly obtained dead reckoning skills would have alerted him something was up and urged him to turn back before making that trip.

In theory, the simple geometric process of plotting lines on a paper chart derived from the speed and direction traveled from each previous plot is highly accurate. Where it stumbles, however, is when the information is not accurate, which can happen for many reasons, both technical and personal. On the technical side, compass inaccuracies, faulty speed-log readings, set (direction of current) and drift (speed of current) data, crosswind/sea effects, and having your towed Walkers Log (distance) mistaken by a large fish for a snack all play a part in telling you where you aren’t.

 In the cockpit, a crewmember confers with the helmsman about the average course steered during his watch, and contemplates a course change. 

 In the cockpit, a crewmember confers with the helmsman about the average course steered during his watch, and contemplates a course change. 

Key to good navigational practice when it comes to your crewmates: trust but verify. Coming off watch they will often give inaccurate information about their turn at the helm, like forgetting to tell you about the major diversion they took to avoid running into that container ship in the middle of the night. Not to mention, as we know, some people’s DNA just makes it completely impossible for them to steer an accurate course line, try as they might.

Running up the outside of the Bahamas on a trip from San Juan, Puerto Rico, to Fort Lauderdale, one of our crew members kept expressing his fear of running aground on the Silver Banks, despite our course taking us well east of them. As our dead reckoning showed us closing in on the Hole-in-the-Wall (the channel between Eleuthera and Great Abaco), something was wrong. We should have been well within sight of land, but we weren’t. On a hunch, I went on deck that night only to discover the fearful crew member steering 15 degrees above course, still determined not to run into his dreaded Silver Banks—which, by the way, we had already safely cleared several hundred miles ago.

To assist in his need for position verification, the navigator would also use any available radio-based navigation aids, such as Consol (Consolan), Decca, and the Radio Direction Finder (developed during World War II), followed in succession by Loran A, Loran C, Transit, and ultimately GPS.

Uncertain of trusting the early GPS system, I became a fan during a family cruise on Long Island Sound in the early ’90s. After a comfortable night moored in a small New England cove, we set out early for Watch Hill, Rhode Island, and quickly ran into a pea-soup fog. The VHF channel was like a comedy show, lit up with dozens of nervous mariners asking each other if they had any idea where they were, with predictable responses. As usual, we had our paper chart open and were doing dead reckoning plots, while ringing the bell and keeping a sharp eye out for other boats, with visibility down to about five feet ahead. We had a GPS on board (one of the very early commercial models). We didn’t really trust the thing but had reluctantly plugged in the coordinates to the small red can buoy that marks the narrow channel entrance to Watch Hill.

As the hours passed, my crew (wife and son) began to doubt that we would be able to find it.

“Don’t worry, we’ll nail it,” I assured them, expressing a level of confidence far removed from what I was actually feeling.

Things got tense as we approached, and I decided to trust the GPS position over our manual plot. A yell from my son came just in time for me to avoid hitting the can, head-on.

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A short while later, safe at anchor with well-earned icy beverages in hand, we stared admiringly at the mighty little GPS, feeling a collective wow.

Of course, if every yachtsman had GPS back in the early days, none of these stories would exist. We wouldn’t have experienced the uncertainty, anxiety, and, once in a while, sheer terror of not knowing exactly where we were at the end of a long passage, approaching an uncertain landfall. But nor would we have experienced the adrenaline rush, the pride, or the exquisite satisfaction of making a safe landfall. No technology in the world could ever replace that feeling.

While respecting the precision of modern navigation, the Rembrandt in me mourns a little for days like those experienced by our real-life and fictional maritime heroes: Magellan, Columbus, Nelson, Hornblower, and others who, never quite certain of their position, artistically exercised skills learned and earned by hard experience and gut instinct. 

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