The last navigator

Do you really prefer hitech modern satellite navigational gadgets to the romance of the stars and traditional methods, asks a friend? Actually, I think the question raises another: is there really a low tech traditional method in our modern sense of it? For most people, tradition means compass, sextant and chart.

A Micronesian sailing canoe, from The Last Navigator

As I mentioned in an earlier post, I have been catching up with a second hand copy of The Last Navigator by Stephen D Thomas, printed in 1987, which explains exactly how Polynesian navigators have been achieving remarkable feats of accuracy for thousands of years before even the compass was invented, let alone the sextant. The book has underlined for me how hi-tech our “traditional” methods of navigation really are.

A diagram of a sailing canoe from The Last Navigator

For the last 250 years navigators have in reality relied on precision instruments and almanacs full of mathematical calculations of great sophistication. These are methods, materials and advanced technologies that would have astonished the ancients.

A maritime chronomoter, key to longitude measurement, was a major technological achievement of the 18th century, while in its day the modern sextant was a leap forward in precision engineering. It simply was not possible before the 18th century to make instruments of such accuracy.

A great deal of learning and practice went into using both chronometer and sextant, in combination with the immense data resources published in nautical almanacs and the even bigger resource of worldwide nautical charts created by meticulous surveying.

Actually, you don’t even need to learn where all the stars and constellations are to use a sextant. The tables tell you where to look, using your compass and sextant and a rough approximation of how far you have gone since your previous position fix. That surprised me when I learnt how to use mine (a late starter because it was only 20 years ago). There is satisfaction in being able to find and recognise the constellations and the main stars from memory, but it is not at all essential.

Contrast all that with the methods of Polynesian navigators. They are well known to have had no instruments and charts, and to have relied entirely on reading the stars and waves and watching for birds and sea creatures. An aura of mysticism and magic surrounds those achievements. But The Last Navigator brings out the detail of how they actually did it, and it reads as an astonishing feat of memory and long practice, which in its underlying method turns out to connect directly with what we do nowadays.

They used the rising and setting positions of many different stars as their compass; they read information about currents and directions in subtle changes in wave patterns and the surface ripples of water; and bird and sea creature behaviour gave them information about distances from land.

In their heads, they carried the equivalent of a chart of Pacific islands. They fixed their position on it by seeing, in their minds, where lines from the rising and setting points of stars on the horizon intersected, using a reference island chosen for the particular passage they were on.

It was the use of position lines that I found most intriguing. Far from being some unknowable ancient and mystic puzzle, Polynesian navigation essentially did what we do now. Underneath everything was a geometry common to all methods of position fixing. Finding the intersection point of lines from stars and other known objects is the basis of every type of navigational position finding.

Intersecting lines are used by the computer in your GNSS receiver to calculate a position using signals from satellites. “Traditional” navigation using a sextant and chart uses lines measured from precise instrument readings of angles in the sky. For thousands of years Polynesian navigators have achieved a similar feat using no aids at all but memory, observation and experience.

If you want truly to learn to navigate with the romance of the stars and a deep understanding and feel for the natural world, you will have a long way to go. According to Wikipedia, by 2014 these skills were still taught only in the outlying Polynesian island of Taumako in the Solomons.

A new edition of The Last Navigator is still available in paperback, though search now under Steve Thomas, not Stephen D. The charm of the book is that it combines the story of a young man’s ocean adventuring with his quest to be taught the old arts before they disappear.

I also found on Amazon what looks like a much more detailed manual of techniques: We the Navigators: Ancient Art of Landfinding in the Pacific by David Lewis. If I could find a copy for less than £30 I would buy it! There are several blogs for enthusiasts of Polynesian and Micronesian navigation and quite a few replicas have been built to sail.

March – Spring and fever

Our plans are changing rapidly, just like everybody else’s in all walks of life in Europe. Sailing now has to be a peripheral concern, but we still have to work out what to do with the boat, and indeed whether we can sail it at all this year.

No sooner had we decided to go to southern Brittany rather than our original destination of Spain than the fight against the Covid 19 virus made that new plan difficult and probably impossible. It is only a couple of weeks since we applied for a 12 month mooring for Spring Fever at Arzal on the lovely River Vilaine: not surprising we haven’t heard back, because southern Brittany has a local concentration of infection, and the marina is now preoccupied with far more urgent matters. It has announced a strict plan to protect its staff and customers.

In any case, the outlook now is for a continuation of virus defensive measures right through the summer and into autumn. Even if there is a relaxation after the first three months of restrictions, current official projections suggest that there is a high likelihood that it will be temporary, with a further set of measures later. There is a strong probability that the emergency will last a year.

So even if we were welcome in France – which we certainly would not be during this next three month phase of the virus – we could never be sure of getting back to the boat from England after we left it there.

Pin Mill, on the River Orwell near Ipswich, the Butt and Oyster pub on the left

One fall back plan is to have a nostalgic sail up the channel and round to Essex and Suffolk, and keep the boat there for a while, if conditions ease.

A sail up channel is enjoyable (you scoot along, riding the flood tide, for a full 11 hours from Beachy Head if you time it right) so fingers crossed that we can at least go sailing at some point. It will be quite a while before we’ll know whether that is achievable.

In the meantime, there is no point in rushing this spring’s work programme, and some of it could wait till next winter.


(1) An email 24 March from Cowes Harbour Commission saying our boatyard, Cowes Marine Services, is closed indefinitely to customers and contractors. So are Shepherds marina and Cowes Yacht Haven, which made the announcement earlier. Terrible news for the people earning a living from working on our boats, but expected.

(2) One reason for wintering on the continent was to keep our EU status at the end of the transition period on 31 December. Will Boris Johnson’s government stick to its pledge not to ask for an extension, given everything else that is happening? If they give in and ask, we’ll have more time to get to France – next year.

Relearning old navigation lessons

Two letters in the latest issue of the excellent Cruising Association magazine* claim it is now safe to rely entirely on electronic charts because backups to the boat’s main chartplotter are so cheaply available. You can leave your old paper charts abandoned in the bottom of a locker somewhere, the argument goes.

However, while researching updates for the yachtmaster book I mentioned last month, I’ve been re-reading intensively about old fashioned navigation techniques I learnt a long time ago, some of which were beginning to fade from memory. It has reinforced for me how important it is to avoid total reliance on electronics and have a portfolio of navigation skills including the old ones.

Traditional chart table at the end of a sail home from Scotland, and the bottle we brought back to celebrate our return .

So I think discussion of electronic charts needs to be a lot more nuanced than some of their more enthusiastic users suggest. Yes, on Spring Fever we have also relied heavily on electronics for many years, but my worry is how easy it is for phone, tablet and laptop software as well as hardware to fail, which can take a long time for the less than totally expert to sort out on passage.

It is certainly true that most well equipped offshore boats will have one or more extra chartplotters loaded on tablets, phones and laptops. Some are backups in case the main plotter system run from the boats batteries fails – that only takes a bust alternator or an engine that refuses to start. I also hear that an increasing number of people are dispensing with dedicated marine chartplotters altogether and relying on tablets etc.

Two examples of what can go wrong: my tablet’s GPS receiver failed last year. After a great deal of googling back home I found out why – I had not updated it for the GPS clock change that took place last year (little noticed, but the navigation equivalent of the millennium bug in 2000). Updated this winter using wifi at home, the GPS started working again, ready for this season. Hands up all those who knew about this and fixed it in advance. My problem was an older tablet. Recent ones would have updated for it automatically.

This was specifically a US GPS problem, and I don’t think it affected the wider GNSS, which includes the Russian, European and Chinese satellites processed by newer receivers than the one in my tablet.

More seriously, my laptop had earlier ground almost to a halt because of some unknown and untraceable software issue picked up I know not where – probably not a virus, or at least not one my Norton protection could find. I abandoned it for navigational backup and planning in favour of the tablet, well before that too showed it could let us down.

This winter, having bought a new laptop, I did a factory reset on the old one, wiping everything except the Windows 7 operating system. Miraculously, it now works like new. So I have loaded the charts, GPS driver and related software again and it is going back on the boat and staying there. I will keep it bug free by not connecting to the internet.

The laptop will be used for planning, with the cockpit chartplotter still our main instrument. But the laptop is old and has a hard disk drive rather than a solid state one, so can mechanically wear out. We may add a further backup in the shape of a small, cheap 7 inch tablet from that’s tough and cockpit proof. (£170 loaded with 2020 raster charts for the UK, France and Atlantic Spain and Portugal).

Computer hotshots might have done fault-finding at sea or in a marina but it took me a whole day at my desk to figure out the laptop solution and sort it, using a high speed internet connection. The software fault had even disabled the DVD drive, which is now working again.

This is not the end of the list of issues. Tablet and phone navigation relies on apps and they do sometimes misbehave. Often the solution is to uninstall and download again – not an option for us at sea. That problem cropped up last year not with a chartplotter app but with one of the best tide prediction apps, though it could easily have been one of the chart apps. This all tells me – a reasonably capable but far from expert user – that the issue of electronics reliability, even with multiple backups, is complicated.

And that is without more basic questions, the first of which, GNSS reliability, I have covered in two previous posts. (On that subject, I have just read a report that GPS spoofing equipment can now be bought for only $100, and how to use it is widely discussed on line).

There is of course the more widely considered question of what happens to your backup tablets, phones and laptops in a knock down, a partial flooding of the saloon, a fire that you may put out but which causes damage or – a nightmare – a lightning strike.

I’ve had a strike on a previous boat, while it was moored on a river – I was ashore – and it destroyed all the electronics and made for a large insurance claim. High voltages nearby can induce large currents in equipment even if it is not wired into the boat’s own circuits. The advice I hear to stick your laptop, tablet and phone in the oven to shield them if lightning is near I find the complete opposite of reassuring!

So we don’t plan to chuck the paper charts, dividers, almanac and ruler in the bottom of a locker somewhere – they’ll always stay ready in the chart table, and we’ll use them from time to time so as not to forget how.

By way of contrast: now reading this 1987 book, which makes even our traditional navigation seem hi-tech. It’s about the last island outposts of Pacific Ocean navigation skills going back thousands of years, which use only knowledge of stars, waves and birds, and no instruments, achieving remarkable accuracy.

* Cruising, Spring issue.

Bowsprit – pronounced bow, bo’ or bogh?

How do you pronounce bowsprit? I’m usually against language pedants, who try to foist the views of Victorian grammarians onto the 21st century. But this word is my one little obsession, ever since getting a letter into Yachting Monthly on whether the first syllable of bowsprit should rhyme with dough or cow.

I was reminded by contemplation of this lovely boat recently.

I can’t remember why or when, but I learnt to pronounce bowsprit to rhyme with dough as a child. In fact, the similar word bowline is always pronounced like dough. So why the difference?Nobody contradicted me on bowsprit till adulthood, partly, I suppose, because I did not know anyone with a boat with one.

But once I met people who used the word practically rather than just read about it, I found myself in a tiny minority: indeed, a handful of people I met were so irritated by my pronunciation that I wrote to Yachting Monthly for a ruling.They published the letter and the deputy editor sent me a private note saying he agreed with me that it should rhyme with dough – but it was obviously too sensitive an issue for such an important journal to take sides in public!

The Oxford English Dictionary agrees it should rhyme with dough, deriving the bow in bowsprit from Middle Low German and Middle Dutch. The online OED can speak the word, too, and it is my way.

I know I am being a touch inconsistent, because I am also convinced that language should evolve the way people actually use it, and not be held back by pedants (see books by David Crystal and David Shariatmadari).

So mine may be a losing battle. The reality is that the pronunciation of bowsprit has changed with popular usage – but don’t expect me to give in any time soon….