Close counts in navigating the old-fashioned way

Sextants are selling briskly. This is about as unlikely as typewriters, another mechanical device rendered obsolete by technology, selling like hotcakes.

I suppose you could make a case for buying a sturdy manual typewriter (available only from eBay or shops specializing in used, outmoded oddments) as a backup. After all, cyber-terrorists, worms or viruses could sabotage the computer network that processes these words, electric power could be lost in a prolonged black-out, the sky could fall.

Silly? Maybe, but it’s essentially the same rationale used by sailors who invest a fair amount of time and money learning celestial navigation and acquiring the requisite equipment: A prudent bluewater sailor needs a manual navigational backup in case the sky—or at least the satellites in it—really does fall.

Our dear friend the Global Positioning System has never failed us, of course, and anyone smart enough to by a cheap handheld GPS receiver and a handful of batteries is immune to electrical navigational failures on board. So worrying about GPS failure is a lot like losing sleep over a tsunami coming ashore in Omaha, Nebraska.

Or is it? Consider the following news, reported first by The Business, a British weekly: The United States would shoot down European navigation satellites if their signals were not turned off or degraded in war time. The threat was reportedly made at a conference in London during a discussion about Galileo, the constellation of 30 satellites the European Union and European Space Agency plan to put into operation in 2008.
U.S. officials were not too thrilled about the Europeans competing with our GPS in the first place. Then they got more irritated when China became a partner in the enterprise and the Europeans proved to be less than accommodating on the issue of shutting down the system in the event of hostilities so it couldn’t be used against the U.S. or NATO. The American threat to take what was euphemistically termed “irreversible action” followed.

An agreement will probably be worked out before Galileo is in service, but the dispute begs the question: If we can shoot down their satellites, can someone do the same to ours?

All the more reason for celestial backup, says Ken Gebhart, whose Celestaire Inc. claims to sell more sextants than any company in the world. In spite of the ubiquity of GPS, sales of the instruments, with prices ranging from $19 (for a cardboard assemble-it-yourself model) to more than $1,500, have been increasing, as has interest in learning celestial navigation. Gebhart’s seminars at sailboat shows are packed. Besides the prudent folks who want a hedge against the day the satellites fail, sailors who attend are intrigued by celestial navigation, Ken says, because “it’s cool and it’s tradition.” He estimates that about 20 percent of the people who learn it actually use it.

Jim Dean is a longtime member of the 20 percent club. A retired English professor who cleverly segued into a writing career that actually requires him to go sailing (his byline regularly appears in SAILING), Jim taught celestial navigation and other traditional sailing skills for many years as a guest expert on Star Clipper sailing cruise ships. Last summer on a transatlantic jaunt from Antigua to the Azores and England on an Oyster 43 (which, of course, had a perfectly good GPS chartplotter), he and the owner, another old salt with a soft spot for sailing tradition, kept the ship’s sextant humming with as many as four sunsights a day. The navigators painstakingly worked out their solutions both manually using H.O. 249 sight reduction tables and with PC software. The results were reassuringly consistent, a testament to skilled sextant work.

Unfortunately, that didn’t necessarily mean they were accurate. Comparison with the GPS position showed a reoccurring error of 30 nautical miles. If the GPS had fetched up, the navigators might have made their landfall in Portugal instead of the Azores. The problem apparently was in the sextant.

That’s something to keep in mind about celestial navigation—its accuracy is not to be confused with that of GPS.

With a properly functioning sextant, a crack celestial navigator can consistently get fixes within five miles of reality. Crude compared to the GPS margin of error of a few meters, but certainly close enough if you lost electronic navigation capability in, say, the vast reaches of the Southern Ocean. So, do the daredevils who regularly sail in those godforsaken waters in around-the-world racing and record chasing keep a trusty sextant handy?

Brian Hancock (another SAILING contributor), who has sailed in three Whitbread Round the World Races, campaigned an Open 50 in singlehanded competition and has worked with management teams for a number of around-the-world races, says he “would bet that 80 percent of the top offshore navigators have no idea how to use a sextant.”

“I always carried one,” he says, “but only for sentimental reasons. I like the look of a sextant.”

Don’t underestimate the importance of the look. Put yourself in a Winslow Homer painting—sextant in hand, sou’wester on head, braced at the shrouds, poised to shoot the sun when it winks through the steely clouds. This must be what Ken Gebhart meant by cool.

Brian hastens to add that he knows how to use a sextant, “but I have not plotted a position in over 20 years and would likely make a call (or send an e-mail) to find out where I was rather than dig out the sight reduction tables.”

Racers in the Vendée Globe were required to carry a sextant, though Bruce Schwab, the only American in the race and ninth place finisher says, “It’s hard to imagine needing it.”

Bruce says he hasn’t done a sight since 2002 “and would fumble a bit at first if I had to do it again.”

According to Brian Hancock, the preferred backup to GPS for circumnavigating racers is a satellite telephone. “They call race HQ and ask for an Argos (satellite) poll to find out where they are.”

Satellites backing up satellites is the way it is for the U.S. Navy too. There is probably a sextant on board every warship, but how adept the officers are at using it is another story. Celestial navigation is still taught at the Naval Academy. Midshipmen get three weeks of classroom instruction on celestial theory, though apparently no exercises in the mechanical skills of the sextant.

I don’t lose sleep over the sky falling or satellites failing, but I’m all for recreational sailors mastering celestial navigation. The ethic of the self-reliant sailor demands it.

Real sailors don’t depend on satellites, even though they know that without them they’re never sure of exactly where they are.