To speak of the ‘discovery’ by European navigators of lands that had long been inhabited by other peoples is obviously absurd, if not insulting, but since the focus of this book is a European invention Europeans unavoidably take centre stage. By way of contrast, I have mentioned briefly the extraordinary skills of the Polynesian navigators, who found their way across the wide expanses of the Pacific using neither instruments nor charts long before the arrival of western explorers. Their achievements deserve to be better known, but they have been well described by others,10 and this is not the place in which to discuss them more fully.
This is not a ‘how to’ guide to celestial navigation, but I hope I have given enough information to enable the reader to grasp its basic principles. I have also tried to give some sense of what it feels like to navigate across an ocean in the old-fashioned way, with sextant and chronometer. Many of the great explorers who wrote about their experiences did so for fellow professionals who needed no explanations, while those who addressed the general public must often have supposed that descriptions of celestial navigation would make dull reading. Anecdotes from Slocum and Worsley have helped me to fill this gap, but I have also drawn on my own – far more modest – experiences, including those recorded in a journal I kept when sailing across the Atlantic as a teenager forty years ago.
For 200 years mastery of the sextant was a vital qualification for every ocean-going navigator. Hundreds of thousands of young men (women seldom had the opportunity) worked hard to learn the theory and practice of celestial navigation, and experts wrote manuals that sold in large numbers to cater for their needs. But the use of the sextant is now an endangered skill that is most commonly learned only to provide a safety net should the now ubiquitous Global Positioning System (GPS) fail.11 Very few practise taking sights at sea as a matter of routine, and most sailors now rely almost entirely on electronic navigation aids. The sextant, if not yet forgotten, has been relegated to a very occasional understudy role. Almost without notice the golden age of celestial navigation has drawn to a close.
If this book has an elegiac tone, it is not merely an exercise in nostalgia. I hope and believe that the sextant has a useful future – that it is not destined to join the many outmoded scientific instruments preserved only in museums. It would, of course, be more than a little eccentric to dismiss the convenience (and reassurance) of electronic guidance systems, but reading off numbers from a digital display is a very thin, prosaic experience compared with the practice of celestial navigation. GPS banishes the need to pay attention to our surroundings, and distances us from the natural world; although it tells us precisely where we are, we learn nothing else from it. Indeed unthinking reliance on GPS weakens our capacity to find our way using our senses. By contrast, the practice of celestial navigation extends our skills and deepens our relationship with the universe around us.
What could be more wonderful than to join the long line of those who have found their way across the seas by the light of the sun, moon and stars? Just as interest in classic boats, built in traditional ways and shaped only by the demands of beauty and seaworthiness, has undergone a revival, so the joys of navigating with a sextant are now ripe for rediscovery.
Sextant: I was nine years old when I first heard that magical word. It was 1963 and I had gone with my family to see Mutiny on the Bounty, starring Trevor Howard as the notorious Captain Bligh, whom he played as a choleric middle-aged martinet, and Marlon Brando as his infuriatingly condescending, toffee-nosed first officer, Fletcher Christian.fn1 A luscious, big-budget movie, shot in the South Pacific around Tahiti, it ends with the burning of the Bounty by some of the mutineers after their arrival at the remote (and then incorrectly charted) Pitcairn Island. Fletcher, the leader of the mutiny, tries in vain to save the ship and, before abandoning it, calls out over the roar of the flames to his friend:
Fletcher: ‘Have you got the sextant, Ned?’
Ned [unable to hear]: ‘What?’
Fletcher [shouting desperately]: ‘Have you got the sextant?’
Ned: ‘No!’
[Fletcher dashes for the companionway that leads to the Captain’s cabin below the burning decks]
Ned [yelling in alarm]: ‘You can’t go now – it’s too late, Fletcher!’
Fletcher [rushing below regardless]: ‘We’ll never leave here without it!’
Fletcher dives into the blazing cabin and is horribly burned trying – in vain – to recover the precious instrument, later dying on the shore as the ship goes down in a shower of steam and sparks.
*
My father loved astronomy and, as a civil engineer, he had been trained in surveying and map-making. It was he who first showed me the night sky when I was a very small boy, standing in our Hampshire garden on many cold, clear winter nights beneath the dark Scots pines. He taught me to recognize the flattened ‘W’ of Cassiopeia, the great torso of Orion, and Ursa Major (the ‘Big Dipper’) with its twin pointers – Dubhe and Merak – that lead the eye to the North Star: Polaris. The Milky Way, I learned, was a galaxy composed of billions of stars to which our sun and solar system belonged as just one very small element.
As we left the cinema I asked my father what a sextant was, and why it mattered so much. I do not remember exactly what he said, but I gathered that it was a device for fixing your position anywhere in the world, on land or sea, by reference to the sun and stars – and that it was a vital tool for navigators sailing out of sight of land. Coupled with the terrifying image of Fletcher Christian diving into the inferno, his words caught my imagination: the thought of being marooned for ever on a small, remote island, unable ever to find the way home, was haunting. How could so much depend on one small instrument? And how could the unimaginably distant sun and stars help a sailor find his way across a vast ocean?
This was the beginning of my fascination with the art of navigation. I lived in a town on the south coast of England where sailing was a part of everyday life, and I first went out in an old-fashioned clinker-built dinghy with my parents when I was not much more than a toddler. I still remember dozing off on a sail-bag, tucked up under the half-deck, listening to the slap of the water on the bows, hypnotized by the gentle, broken rhythm of the waves. Later I sailed a dinghy of my own and crewed racing yachts, but I never much liked competitive sailing. What I loved was pilotage – the business of reading a chart, plotting a course, making allowances for compass variation and the effects of tidal streams, and all the other tricks of the coastal navigator’s trade.
Charts fascinated me. Those published by the British Admiralty were then still printed from engraved plates, and their appearance had not changed much since the nineteenth century. They had a solemn gravity, reflecting as they did the accumulated data of generations of dedicated marine surveyors. The traditional saying – ‘Trust in God and the Admiralty chart’ – was a measure of their exalted reputation. Unlike their metric successors, the old charts were soberly black and white. Prominent features on dry land that might be useful to the navigator – like church steeples or mountains – were shown, and detailed views of the coast were often included in the margins to aid recognition of important landmarks or hazards: the old surveyors were all trained as draughtsmen. Wrecks were marked with a variety of warning symbols depending on how much water covered them; those that broke the surface even at high water were marked with a grim little