Читать книгу Sextant: A Voyage Guided by the Stars and the Men Who Mapped the World’s Oceans - David Barrie - Страница 13

Day 6: Up again at 0400. Colin says we’re very close to where the Titanic went down. More fabulous weather with wind S force 2–3. Sighted a Sanko Line ship and tried to raise her on the radio-telephone – no luck. More sextant practice.

After supper Colin talked about his time as Gunnery Officer on board the battleship Prince of Wales when she and the battle cruiser Hood were in pursuit of the German battleship Bismarck. When the battle started Bismarck had the ‘windward station’ – this gave her an advantage, just as in the days of sail. Bismarck’s rangefinders were pointing downwind whereas Prince of Wales and Hood were ploughing into heavy seas that showered theirs with spray. If Colin’s guns had found Bismarck’s range sooner she would have had to alter course and maybe Hood would have survived. But Prince of Wales did manage to score a crucial hit on Bismarck.¹ There were tears in his eyes.

We also talked about the Battle of Jutland. Colin said that the British Commander-in-Chief had struggled to determine his exact position as he was closing with the German fleet because poor visibility had prevented any sights being taken. Strange to think that these great warships relied on sextant and chronometer to find their way – just like us. ²

Saecwen was not much better equipped in navigational terms than the Bounty. Like Bligh we steered by magnetic compass and fixed our position by the sun and stars. It is true we had a ‘Walker’ log to measure the distance we travelled through the water – a mechanical device that sat on the stern counting the turns of a brass impellor that we trailed behind us. This was more sophisticated than the kind of log that Bligh would have used, but it was still a piece of nineteenth-century technology. In addition to an old-fashioned lead-line, we had an electronic echo sounder and a radio direction-finder (RDF), both of which would have amazed Bligh. But the echo sounder could measure depths down to a few hundred feet at best, so it was helpful only in coastal waters, and since the marine radio beacons had a range of no more than a couple of hundred miles the latter too was of little use to us in mid-ocean. Fairly accurate radio-based navigation systems, like LORAN, had been developed during the Second World War, but the receivers were bulky and expensive and we did not have one. Early forms of satellite navigation were already available but only for military purposes, and GPS was still on the drawing board. We carried a radio-telephone, which turned out to be very temperamental, but apart from flares we had no other means of calling for help in an emergency.

Saecwen herself was ten years old, and handsome without being flashy. She would now be regarded as a ‘classic’ yacht. With a long, deep keel, she was slow and heavy by modern standards, and a bit the worse for wear after her tough outward passage across the Atlantic. We had already had to repair some of her sails, and rust stains were starting to trickle down her white topsides. Most new yachts were already being built of glass fibre-reinforced plastic (GRP), with aluminium masts and stainless-steel rigging and deck fittings, but Saecwen was old fashioned. She was built almost entirely of traditional materials – a teak deck, with a wooden mast and hull of copper-fastened mahogany planks on oak frames. Beneath the sliding main hatch – at the forward end of the cockpit – a few steps descended into the cabin. The galley, with a small two-burner gas-fired stove and a tiny sink, was immediately on the left, while the chart table with the temperamental radio-telephone and RDF set lay on the right.³ Beyond the galley and the chart table was the saloon, a space perhaps 10 feet by 8 with a table in the middle and a settee berth on either side. It was lined with lockers – one marked with a red cross for the medical kit – and there were small bookshelves with bars to hold in their contents in heavy weather. Three oblong windows let in light at deck level on either side. Beyond the main bulkhead lay the ‘heads’ – a miniature pump-action lavatory – and the fo’c’s’l where there were two more berths and stowage for oilskins and sails. Small electric lights were dotted around the cabin but most of the time we relied on brass oil lamps.

Below deck Saecwen had a very particular smell I can still vividly recall – a musty mixture of damp timbers, diesel oil, paraffin, oilskins and dirty clothes, coupled with the scent of the ripening fruit and vegetables in the cargo nets overhead. Not very appealing perhaps, but it was far better than the sharp scent of epoxy resin that never quite vanishes from GRP boats. Being built throughout of wood Saecwen even sounded different from a plastic yacht: footsteps on deck and the thump of waves against the hull were muted and distant, and partly for that reason her white-painted saloon felt especially cosy. The eighteenth-century navigators would have felt quite at home aboard her.

The fast-spinning impellor that trailed at the end of the log-line skipped through our boiling wake as we continued reaching fast to the east under full sail. We passed through patches of yellow Gulf weed, and a sharp dorsal fin slowly zigzagging through the water, like a hound picking up a trail, revealed the presence of a large shark. A half-inflated purplish plastic bag floated by, a depressing reminder of man’s polluting habits, until on closer inspection it turned out to be a Portuguese man-of-war – a medusa, trailing its long blue fringe of stinging tendrils.

The fine weather continued and we fell into an easy routine, eating together, taking sights and otherwise either sleeping or standing watch – four hours on, four hours off at night for Colin and me, with more flexibility during the day when Alexa helped us out. Every twenty-four hours we recorded good runs of 150 miles or more, the fore hatch stood open and the steady draught of warm air gradually dried out everything down below. On deck everything was now covered with a sparkling rime of salt crystals. We hardly had to touch the sheets, and the self-steering gear⁴ kept us on a steady course relative to the wind. Apart from navigation and preparing food, there was little to do apart from keeping a lookout, reading and occasionally writing up the log.^fn1 We kept a close eye on the western sky for any change in the weather – sometimes clouds would pile up as the sun went down, but then the night would be clear and dawn would bring in another perfect day. The barometer remained high and steady; even Colin had rarely known such beautiful sailing.

‘Food’, I wrote in my journal, ‘becomes a major interest and it matters far more than usual that it should be good. In fact good fresh food on a plate and plenty to drink are the main things one misses. Also keeping reasonably clean.’ We still had some apples, potatoes, eggs and onions, but otherwise most of our fresh food had run out. We carried 35 gallons of fresh water and used this only for drinking; our rice or potatoes were boiled in seawater. We all now looked disgusting, with filthy, lank hair and – in Colin’s case and mine – increasingly stubbly cheeks.

People sometimes complain of the monotony of the sea, but it is, with the sky, the most changeful of all natural spectacles. Its surface, brushed by the wind, whether gently or with violence, presents patterns of infinite variety, and its colour too undergoes astonishing transformations, depending on factors like the time of day, the depth of water and the weather. But despite the ever-changing vistas of sea and sky, time passed very slowly and I often found the close physical confinement trying. We spent almost all our time either on watch in the narrow cockpit, a space perhaps 7 foot by 5 with the tiller in the middle, or down below in the saloon. This was a bit bigger, but there was very little room to move around, and at more than 6 foot I could not stand upright. In fine weather I would often sneak off to the foredeck to read. There was nowhere else to go but overboard. We were getting very little physical exercise and this probably contributed to my sense of frustration and impatience: sometimes I felt like screaming.

Colin deliberately did not plot our position on the small-scale North Atlantic chart until we were well on our way, and even then it looked as if we had hardly made any progress. This was not surprising given that we were crossing 3,000 miles of ocean at a rate seldom faster than a brisk jog. The possibility that the weather might change for the worse was always on our minds, as we knew we would be lucky not to encounter a gale at some point. The condition of the boat was also a concern – we ran the engine for an hour or so every few days to charge the batteries, pumped out the bilges (counting how many strokes it took to assess how leaky the boat was) and watched the sails and rigging for signs of wear and tear. Sometimes we had to carry out minor repairs. The sliders that attached the mainsail to the track running up the mast often came loose and had to be reattached, and we sewed up a seam on one of the foresails where the stitching had worn out. The steering compass too caused problems: the fluid in which the compass card floated began to leak out and a bubble appeared in the clear plastic bowl that covered it. As the bubble steadily grew it became harder to read the course, so we dismantled the binnacle, found the leak and patched it up with chewing gum. We then topped up the fluid with gin, but the operation was not a complete success – a small parcel of air obstinately wobbled at the top of the bowl, and the cost in precious liquor was high.

One day a bird landed on Saecwen’s deck – some kind of flycatcher, I think – so exhausted that it made no attempt to move when I offered it some water. Eventually it fluttered away. How it had reached us and where it was going was a mystery. As our distance from the land steadily increased, some part of me was always anxiously aware of the immensity of the ocean, the miles of water fading into chilly darkness beneath us, and the almost ludicrous smallness and fragility of our 35-foot boat.

*

Despite our compass problems, our sextant and chronometer told us where we were to within a few miles. The exotically named Admiral Sir Cloudesley Shovell was less fortunate when, on the night of 22 October 1707, he entered the English Channel with twenty-one British warships under his command. The fleet drove on to the reef-strewn Isles of Scilly, which were then guarded only by a single lighthouse on the island of St Agnes, and four ships went down with the loss of some 2,000 lives. Shovell himself was washed ashore and reportedly murdered by a local woman who fancied a ring on his finger. This notorious disaster, which has often been cited as evidence of the dangers of navigating without an accurate means of determining longitude, may in fact have been caused by errors in the assessment of the fleet’s latitude, or by mistakes in the recorded position of the Scilly Isles⁵ – quite possibly both.

Navigation posed many problems in the days before celestial navigation was perfected and the cause of a wreck can therefore seldom be attributed to any single factor. The notorious loss of the Dutch East India Company ship Batavia in 1629 is a case in point.⁶ She was wrecked on a reef off the west coast of Australia after crossing the Indian Ocean on her way to Java. The reef in question was part of an extensive group of low islands discovered by a Dutch sailor called Frederik de Houtman in 1619, and the Batavia drove on to it under full sail. The lookout had in fact spotted white water ahead but the master, convinced that it was merely a reflection of the light of the moon, refused to alter course or shorten sail. A faulty DR estimate of the Batavia’s longitude might well have encouraged this disastrous misjudgement: the master apparently thought he was 600 miles from land.⁷ Such an error would be quite understandable after a long ocean passage, especially since the prevailing westerly winds in the southern Indian Ocean generate an east-going current that would have been hard to detect. To confirm this, however, it would – at the very least – be necessary to know whether the master was using a chart on which the position of the reef was correctly recorded, and if so where he believed his ship was in relation to it. It is equally difficult to assess the reasons for the loss of the British warship Ramillies, which occurred as late as 1760. Having entered the English Channel, she was caught in a gale off the south coast of Devon and embayed. She tried to anchor but was driven ashore with the loss of all but twenty-seven of her crew of 800. Assuming that her commander knew the latitude correctly, was he mistaken in his longitude? Was the chart he was using in error? Or did poor visibility mean that those on watch failed to notice the approaching coast before it was too late? We have no way of knowing, but the impossibility of accurately determining their longitude put offshore navigators under a heavy handicap.

Commodore George Anson’s circumnavigation of the world provides the clearest illustrations of the navigational difficulties that sailors faced before the longitude problem had been solved. England being at war with Spain, Anson (1697–1762) was dispatched in 1740 with a squadron of ships and more than 1,900 sailors and soldiers⁸ to harass the enemy’s colonial settlements in the Pacific. Long delayed by contrary winds, the squadron reached Madeira – their first port of call – in October, having already been at sea for forty days. The island’s longitude was laid down on contemporary charts – as it happens, quite accurately – in 17° West ‘of London’, but Anson and his men placed it somewhere between 18° 30' and 19° 30'.⁹ Their DR was out by at least 75 miles. Five months later, in early March 1741, having passed through Le Maire Strait, north-east of Cape Horn, Anson’s ships struggled round into the Pacific, facing a succession of terrific gales: men were injured or lost overboard, some lost fingers or toes to frostbite, the ships began to leak heavily and both sails and rigging were frequently damaged. Typhus and dysentery had already weakened the squadron on the voyage south from Madeira, but scurvy too now began to take its toll.¹⁰ On Anson’s flagship, the Centurion, the crew were so much weakened that they were unable to throw overboard the bodies of their dead shipmates. One old soldier, who had fought at the Battle of the Boyne in 1690, discovered as he lay dying that his long-healed, fifty-year-old wounds were reopening.¹¹

On 3 April the Centurion ran into a particularly severe storm:

In its first onset we received a furious shock from a sea which broke upon our larboard quarter, where it stove in the quarter gallery, and rushed into the ship like a deluge … to ease the stress upon the masts and shrouds we lowered both our main and fore-yards, and furled all our sails, and in this posture we lay to for three days …¹²

Despite the appalling conditions Anson and his men were convinced that they had not only rounded Cape Horn but had also made good westerly progress out into the Pacific. Judging that it was now safe to head north, they were in for a nasty surprise. On the night of 13–14 April, when they thought they were hundreds of miles out to sea, the leading vessel caught sight of rocky cliffs – probably the western end of Noir Island off the south-west coast of Tierra del Fuego. She fired a gun and showed lights to warn the ships astern of her of the impending danger:

[the land] being but two miles distant, we were all under the most dreadful apprehensions of running on shore; which, had either the wind blown from its usual quarter [south-west] with its wonted vigour, or had not the moon suddenly shone out, not a ship amongst us could possibly have avoided …¹³

One officer recalled seeing the cliffs rearing up ‘like two black Towers of an extraordinary height’, but every ship managed to get clear.¹⁴

Anson’s own log gave the Centurion’s longitude on 13 April as 87° 51' W, while another surviving log gives a longitude of 84° 12' W just before land was sighted.¹⁵ The difference between these estimates is itself an indication of how difficult it was to determine longitude reliably by DR. In fact the longitude of Noir Island is about 73 degrees West, which means that Anson’s estimate was out by nearly 14 degrees – a distance of almost 500 nautical miles in this latitude. The authorized account of the voyage plausibly places the blame for these very large errors on the unexpected strength of the ocean currents in this locality:

It was indeed most wonderful that the currents should have driven us to the eastward with such strength; for the whole squadron esteemed themselves upwards of ten degrees more westerly than this land, so that in running down, by our account, about nineteen degrees of longitude, we had not really advanced above half that distance.¹⁶

The squadron – from which two ships had already separated – faced further battering by storms as it struggled northwards. By the end of April, as the death toll from scurvy rapidly mounted, each of the surviving vessels found itself alone. Having barely survived a hurricane at the end of May off the island of Chiloé,¹⁷ the Centurion headed for a planned rendezvous at the island of Juan Fernández [now Robinson Crusoe Island] off the coast of Chile where desperately needed fresh provisions could be found. However, to save vital time, Anson ‘resolved, if possible, to hit the island upon a meridian [of longitude]’.¹⁸ In other words, rather than heading north up the coast of Chile and then running down the island’s latitude in the time-honoured fashion, he took the chance of sailing directly for it. On 28 May they had nearly reached the latitude in which the island was laid down and ‘had great expectations of seeing it: But not finding it in the position in which the charts had taught [them] to expect it’ they were afraid that they might have gone too far to the west.¹⁹ Though Anson himself was ‘strongly persuaded’ that he had glimpsed the island, his fellow officers were unconvinced and, following ‘a consultation’, it was agreed that they should head back to the east. They sighted the distant, snow-capped peaks of the Chilean cordillera on 30 May:

Though by this view of the land we ascertained our position, yet it gave us great uneasiness to find that we had so needlessly altered our course when we were, in all probability, just upon the point of making the island; for the mortality amongst us was now increased in a most dreadful degree, and those who remained alive were utterly dispirited by this new disappointment …²⁰

It took nine days to regain the ground they had lost and it was not until 10 June that the Centurion, whose crew at full strength would have numbered between four and five hundred men, at last reached Juan Fernández ‘with not above ten foremast men in a watch capable of doing duty’. This single navigational error had cost the lives of ‘between seventy and eighty of our men, whom we should doubtless have saved had we made the island [on 28 May], which, had we kept on our course for a few hours longer, we could not have failed to have done’.²¹

Once the remnants of his squadron had gathered at Juan Fernández and the surviving members of the ships’ crews had recovered their strength, Anson carried out a raid on a small Spanish coastal settlement in Peru, and also captured a few merchant vessels. He next tried to intercept a Spanish treasure ship that was expected to sail from Acapulco, but news of his presence had reached the Spanish authorities and the ship remained safely in port. Disappointed but undaunted, in May 1742 he set out across the Pacific with his two surviving ships.²² In the course of an agonizingly slow voyage, again greatly complicated by unreliable charts and uncertainties about their longitude, one ship had to be abandoned and the Centurion, with eight or ten men dying every day ‘like rotten sheep’, was barely afloat when she reached Tinian in the Marianas Islands in August.²³

Anson’s determination now, at last, paid off. He was able to reach Canton (modern Guangzhou) where the Centurion was repaired and then succeeded in capturing the treasure ship, Nuestra Señora de Covadonga, off the Philippines. The Covadonga was carrying more than 1.3 million pieces of eight and 35,682 ounces of silver. The exact value of the loot Anson finally brought home in 1744 is uncertain, but as a ship’s captain as well as commander-in-chief, he would have received three-eighths. His share of the treasure from the Covadonga alone may have amounted to the vast sum of £91,000. For comparison the pay due to him in the course of the whole voyage fell just short of £720.²⁴ The captured treasure was paraded through the streets of London to national jubilation, and little attention was paid to the fact that 1,400 men had failed to return home. Propelled by this success Anson was later ennobled and rose to the very pinnacle of the Royal Navy, serving twice as First Lord of the Admiralty.