The Coast of Coral

by Arthur C. Clarke

  Dusk had fallen when the Bruce Highway—which had at least been recognizable as a road until now—played a dirty trick on us. I had been navigating, trying to reassure Mike that we were still on the main road and not lost in some country lane. On the whole it was easier to drive by night than by day, for when the sun was up the shadows of the gum trees lay in bands across the road and concealed many of the potholes, which were revealed much more clearly by the slanting beams of the headlights.

  We had seen no other traffic—or indeed any other signs of life—for many miles, and we were driving under a star-filled sky through a land that was completely wrapped in darkness. There were not even the occasional lights of iso­lated farmhouses, and civilization seemed a very long way off indeed. In actual fact, the nearest town was barely twenty miles away, and anyone from the real Australian “outback” would probably have felt oppressively hemmed in. But after the bright lights of the cities, this was as lonely as I cared to be.

  Suddenly there was a light ahead of us. Standing in the roadway was a man waving a torch, and he had disturbing news. A large trailer had swung across the highway, and it might be hours before any traffic could get through. “But they’re building a bypass through those fields on the right,” he told us. “If you go carefully, you can get the car through there.”

  We dutifully turned off into what appeared to be a roughly plowed field. After a few yards, it was quite pos­sible to decide which was the best—or rather the least im­possible—route to take. Bulldozers had been at work and we were surrounded by embankments of piled-up earth. The only thing to do was to get out of the car, take a flashlight, climb up one of the mounds, and survey the landscape.

  I did this and reported back to Mike that if he could surmount one hillock and then make an Scurve there seemed a good chance of getting through. So we made a run for it, the mounds of earth looking enormous as our headlights picked them out against the utter darkness of the night. For one anxious moment car and trailer see-sawed on top of a crumbling embankment; then the tires got a grip and we were over. After a little more cross-country work, we managed to find our way back to the main road, which to our relieved eyes now had all the attractions of a superhighway.

  The first night on the road out of Brisbane we spent at the little town of Maryborough, which was still in the pro­cess of recovering from the disastrous floods of a few weeks before. All the obvious damage had been cleared away, and a casual visitor might never have known that not so long ago all the streets had been canals. Almost the only visible reminder of the floods was an occasional no­tice in a shop window: BACK IN BUSINESS ON BARE FLOORS.

  The next day, as far as the roads were concerned, was a repetition of the first. From time to time our spirits would be raised by a stretch of smooth concrete, and we would get up to sixty just in time to hit the next section of cor­rugated dirt. Once we passed—with considerable difficulty—a convoy of enormous circus trucks, laden with all the gaudy props and accessories of the Big Top and the Midway. It was hard to see how these huge vehicles could get through some of the places we had negotiated, but pres­ently we found that they had one advantage denied to or­dinary motorists. In the middle of the convoy we came across a truck loaded with elephants, which stood patiently side by side waving their trunks back and forth in hypnotic rhythm. When the trailers were bogged, the elephants could always get out and push....

  Toward evening, over a soggy stretch of freshly laid gravel, we drove into the little port of Gladstone. It had taken us a day and a half to travel four hundred miles, but in the circumstances we were only too glad to have arrived with the car undamaged (as far as we could tell beneath its coat of mud and dust) and all our property intact.

  Gladstone is a landlocked port surrounded by moun­tains and protected from the sea by an island barrier. When we arrived it was very warm and humid, and it was easy to believe that we were now in the tropics. If I had had any doubts on that score, they were dispelled when a weird flying Thing, which I was completely unable to identify as long as it remained airborne, came blundering into our bedroom out of the night. When it finally touched-down on the dressing table it turned out to be a giant praying mantis, a good three inches long. It took quite a fancy to us and didn’t leave until next morning.

  The link between Heron Island and the mainland is the sixty-foot motor vessel Capre, which makes the crossing twice a week. She was due to leave at eight in the morning, so we had taken the precaution of loading all our heavy gear the night before. There was no need for us to have swallowed our breakfasts so hastily, for it was not until ten-thirty that the last stores and tourists had been loaded aboard and we got under way.

  It was a bright, sunny day, with a slight breeze and a gentle swell on the water. The Capre negotiated the chan­nels leading out of the harbor, the mainland fell astern, and we were heading out toward the Reef. An hour after leaving Gladstone, we noticed something that warmed our hearts, and raised our expectations. The brown and turbid coastal waters, stained by the sediment from the still-brimming rivers, were giving way to the deep blue of the open sea.

  An hour later, the first island of the Reef appeared on the horizon. It was not more than a dozen feet clear of the water line, and was thickly wooded so that from the sea it appeared as a tightly packed forest bounded by a narrow fringe of dazzling white sand.

  I stood on the windswept deck of the Capre and stared across at my first coral island. It was lovely, with its gleam­ing beach dividing the blue sea from the verdant forest. Yet there was a loneliness about it, even a desolation, for it was a place that had nothing to do with man. A castaway would soon perish amid all this beauty, the tides and the winds would efface his footprints from the virgin sand, and the legions of ants and crabs would make short work of him.

  An hour and several islands later, our goal appeared as a dark cloud on the horizon, but it seemed a long time before it humped itself out of the sea and we could distin­guish the buildings set among the trees, the rust-stained wreck lying on the edge of the reef, and the little fleet of dinghies and cabin cruisers moored offshore. Almost five hours after leaving the mainland the Capre—which is an unusually fast boat—came to rest at her anchorage a couple of hundred yards from the beach. That was as close as she—or any vessel drawing more than a few feet of water—could get, even when the tide was at its highest. The reef that completely surrounds Heron Island like a vast, barely submerged plateau prevented any closer approach, and the last stage of our journey had to be made in dinghies. We were welcomed on the beach by a large tribe of painted canni­bals from the tourist settlement, who danced round us ut­tering wild cries and were not appeased until we handed over our prettiest lady passenger as a sacrifice. The re­mainder of us walked up the beach into the cool, green shelter of the pisonia trees, trying to realize that what for most men could never be more than a romantic dream had now come true for us.

  Heron Island is typical of its class, being a perfect example of one of the “low islands” which comprise most of the outer regions of the Reef. The phrase “coral island” probably conjures up in most people’s minds a picture of a palm-crowned ring surrounding a still, blue lagoon. This is merely one type of coral island—the atoll—and it so happens that though they are common in the Pacific, atolls are virtually nonexistent in the Barrier Reef. Even the few ring islands that do occur fail to merit the name, for the true atoll rises out of the great ocean depths—a thousand fathoms or more—while the waters inside the Barrier Reef average little over a hundred feet in depth.

  The Reef islands fall into two main classes—the hilly or even mountainous “high islands,” and the “low islands,” which are often little more than glorified sand dunes and may rear themselves less than a dozen feet above the sea. Only these latter are the true coral islands—that is, islands which are literally made out of coral. The high islands are formed of ordinary rock and were once part of the mainland, a change of sea level having cut them off from it. Though they often have
extensive coral reefs around them, the coral grows upon them as barnacles encrust a ship—the islands themselves would have existed whether there was such a thing as coral or not.

  Heron and the other low islands have quite a different origin. Without getting ourselves involved in the argument that has raged among geologists for more than a century, we can regard them as reefs that have managed to stay permanently above the water line, and have acquired a coating of sandy soil in which vegetation has taken root. The process is a continuing one, and the time may come when all those reefs which are now submerged at high tide will become islands.

  It is easy to see how this can happen. Coral cannot live permanently out of the water, yet it needs sunlight so it is continually growing up toward the surface. Eventually it establishes a kind of equilibrium, the tougher corals, which can stand exposure to the air for several hours at a time, forming the upper layer of the reef. When these corals fi­nally die, their chalky skeletons—which often form massive boulders—may be piled up by storm-driven waves so that they form a pin point of land, just beyond the reach of the highest tides. Such an islet, at first only a few feet across, may become a nucleus for future growth. Birds may rest upon it, leaving as a memento the seeds of plants and trees which they have eaten. Drifting debris—sometimes carrying lizards and other small animals—may make further contri­butions to its flora and fauna.

  And so the island will grow from a barren speck in the ocean to an entire selfcontained world of life and beauty—unless the storms which gave it birth destroy it before it can consolidate itself. The war between sea and land is never-ending, and each side has its victories.

  Coral islands can, of course, be formed in other ways. Sometimes the immense forces which lie slumbering in the darkness beneath the earth bestir themselves, and the land rises or the sea falls. This can happen in a few minutes—there is one record of a ship in the Reef area which was lifted out of the water by a rising rock as if on an elevator—but normally it takes millenniums.

  Heron Island is a tiny oval of land only about half a mile long; it can be circumnavigated in a brisk thirty-minute walk along the beach. However, I think it unlikely that anyone has ever performed the feat, because there are so many interesting distractions—flotsam to be picked up, pools to be investigated—that no time limit can ever be set for a stroll. The island is completely covered with a dense forest of pisonia and pandanus trees, the home of thousands of sea birds, and all the buildings that have been erected on the island are set in clearings that have been cut in this small jungle.

  Four times every day, as the tides rise and fall in their eternal rhythm, Heron Island undergoes a complete transformation. At high tide, all that is visible above the water line is the tree-covered sand key, no point of which is more than twenty feet above the sea. But when the tide turns, the water drains away to reveal a vast, flat tableland, and the island multiplies its size a hundredfold as the reef around it is exposed. In some directions, the water’s edge is miles away; at an unusually low tide, the distant sea is no more than a strain of deeper blue on the horizon. Endless acres of coral are exposed, if only for a few hours, to the sightseer who cares to wander among them and explore the contents of their countless pools. (The verb “to fossick” describes this sort of activity; “fossicking” is an old English word imported during the Australian gold rush and now extinct in its country of origin.)

  Although the normal tide range is only about six feet, the coral slopes so gently to the sea that immense areas of reef are exposed in a very short time. And, conversely, as many incautious tourists have discovered, the tide can come in with equally surprising speed. It is all too easy to find oneself half a mile from the shore, wading waist-deep in water and keeping an anxious lookout for triangular fins.

  The reef on which Heron Island stands is a long oval lying approximately in the east-west direction, and the island itself is at the western end of the reef, at the nearest point to the Australian mainland. At low tide, therefore, it is relatively easy to walk right out over the exposed coral until you come to the western edge of the reef, for it is only a few hundred yards from the sandy beach. But on the other side of the island, the reef edge is unattainably remote, except by sea. No one could ever scramble across those miles of slippery and often treacherous coral before the tide turned and they were forced to head back to land.

  This, then, is a thumbnail sketch of Heron Island, and indeed of a hundred other islands in the Great Barrier Reef. It was to be our home for the next six weeks and was to provide us with some of the most exciting, most frustrat­ing, and most dangerous moments of our lives.

  IX

  Heron Island

  Heron Island, like ancient Gaul, is divided into three parts. One is leased to the owners of the tourist center, who have built small, two-berthed cabins which form a compact little settlement complete with its own power plant, refrigeration system, water storage tanks, and most of the necessities of civilized life for an isolated—apart from the twice-weekly trips of the Capre—colony of a hundred people. Another is leased to the Great Barrier Reef Committee; the only build­ings on this portion are the research station (half completed at the time of our visit), the Superintendent’s house, and a small hut which we used as home, photographic laboratory, office, and storehouse for our equipment.

  The remaining portion is the exclusive property of some thousands of noddy terns and muttonbirds (wedge-tailed shearwaters) who form two distinct communities—one nesting in the branches of the pisonia trees, the other dig­ging burrows underground.

  We were met on the beach by Eric Hasting, the Superintendent of the Research Station, who was quite sur­prised to see us as the letter announcing our arrival was still in the mailbag upon the Capre. All our equipment was also out there off the edge of the reef, and when it was finally brought in it monopolized the services of one din­ghy. Visitors to the island are asked to bring not more than two suitcases; we had four or five each, plus half a ton of diving and photographic equipment. It made a most im­posing pile when laid on the beach, and we did not look forward to the task of transporting it a hundred yards or so through the jungle.

  Fortunately the tourist center came to the rescue by lending us its ancient truck; we had hardly expected to meet any motor vehicles on an almost completely wooded island with no roads. When the Capre anchors at low tide, however, the truck is a very useful asset as it can trundle along a ribbon of sand that, in one area, extends almost out to the edge of the reef. Stores can then be loaded and brought back without waiting for the tide to rise high enough to float the dinghies. I am quite sure that, sooner or later, the truck is going to get bogged down somewhere out on the reef, and Heron Island will be deprived of its solitary motor vehicle.

  We piled our equipment aboard the truck, and it set off into the apparently trackless jungle, squeezing dexterously through the thickly set trees and scraping under overhanging branches. Several times the driver had to duck to avoid decapitation, but at least he had no worry about oncoming traffic. We ground through the forest for little more than a hundred yards, but there were so many twists and turns that I got lost a dozen times the first week before I could guarantee to retrace the path.

  The Research Station was so enclosed with trees that it might have been in the middle of Africa; it was hard to believe that the sea was only fifty yards away, and that there was a flourishing holiday resort at about twice that distance. In next to no time, the virgin concrete floors of the lab were covered with air cylinders, cameras, flippers, snorkles, spear guns, weight belts, film processing equip­ment, and all the other impedimenta of our expedition. The landing area around the first lunar rocket would have pre­sented a very similar appearance an hour or so after touchdown....

  Although the jungle on Heron Island is dense enough to provide all the solitude anyone could desire, it is not so thick that one cannot force a way through it in almost any direction. The island, presumably because of the absence of animals, is completely f
ree from plants that scratch or sting. Nor are there any poisonous reptiles or insects; it is safe to walk barefooted even through the densest undergrowth. Safe, yes—but occasionally rather nerve-wracking, owing to the ubiquitous muttonbirds.

  These quite attractive birds, about the size of pigeons, spend all day out at sea foraging for food and return to the island when darkness falls. The sandy soil is literally honeycombed with their burrows, which can make even a short walk quite a hazardous adventure. Without the slightest warning, the (comparatively) solid earth will open up beneath you and you may sink up to your knees in the sand. You may get one foot free, rest your weight upon it in an attempt to extricate yourself—and promptly go through the roof of the muttonbird residence next door. Every year, during their seasonal stay on the islands, hun­dreds of these birds and their broods must, one would imagine, be killed by the collapse of their flimsy homes.

  It seems odd to find birds burrowing underground like rabbits, but on treeless sand keys there is no other way of finding shelter, and the muttonbird has so adapted itself to this subterranean existence that even when it lives in a spot where there are more trees than open ground, it still digs its nest in the soil. At night, if you walk through the forest with a torch, you continually come across these birds squatting outside their burrows and blinking in the sudden light. They make only halfhearted attempts at protest when picked up.