We gazed up at the countless points of light, brightening against the black background. Slowly a galaxy of light took shape, embedded in a black universe. Was there life there? Absolutely.
How could we be so sure? Because we weren't on Earth looking at the sky, but deep inside the Earth looking at the ceiling of a cave covered with Arachnocampa luminosa, the New Zealand "glowworm," one of nature's most curious luminaries.
It was, truth told, the idea of seeing the glowworms that brought my wife and me to Waitomo Caves on the North Island of New Zealand. The "worms" are actually larvae of a fungus gnat; they prey on insects they attract with a blue light. The larvae produce this light with, among other things, a chemical bearing the extraordinary name luciferase. The hungrier a larva gets, the brighter it glows. Glowworms can survive in many places, but they thrive in dark, wet caves, and Waitomo is famous for its colonies of them.
Nearly as renowned is the Kiwiesque way of viewing them. You may walk into one of the caves, but to the daredevil Kiwi mind this is uninspired. "Black Water Rafting" is the way to go. The version of the adventure we chose requires a 110-foot, dead-drop rappel down into a cave, a 50-foot "flying fox" ride across a subterranean river gorge and then an inner-tube trip down the river. The outfitter that provides this service has trademarked the name "Black Water Rafting" to describe the experience.
Behind the Black Water Cafe in Waitomo Caves Village, 10 of us--three strapping Germans, two Scottish women, an American man, my wife and I, and two Kiwi guides--suited up in rubber boots and wet suit, plastic hard hat with headlamp, and, for rappelling, a mountain climber's waist-crotch harness complete with carabiner and safety clips.
Our guides were Stu and Nic. Stu is tall, lanky and goateed. He has a been-there, done-that manner that might be annoying in someone else, but that is a positively reassuring quality in an adventure guide. Nic (Nicola), a former teacher, is stocky, cheerful and direct. Both combine a drill sergeant's air of command with a camp counselor's enthusiasm.
Stu gave us a pointed, two-minute rappelling lesson. We all seemed to "get it" and were graduated to the real thing. Hidden nearby in a clump of ponga trees and bush, the cave entrance was a limestone funnel that narrowed from 20 feet in diameter to a black, three-foot-wide maw. A narrow metal platform went out to the middle of the funnel and then, like a gangplank, simply stopped.
One at a time we had to walk the plank out to mid-funnel to have Stu hook us to the rope and drop us into the hole. Nicola went first. My turn. Stu gave me a shove and said, "You're away!" I slid down into the narrow stem of the funnel, my headlamp shining on the yellow limestone's strata. I hadn't hung from a rope since high school gym, but I was fine, sliding along smoothly. And then suddenly the funnel stem ended and I was in space--big space--and I instantly sensed the distance to the bottom. Somewhere water was roaring, echoing. The big space and booming water spooked me into going faster. Before I knew it, my feet were on solid, if subterranean, ground.
Getting our bearings while waiting for Stu, we stood in a kind of antechamber full of huge lumps of limestone. Our breath fogged our lamp beams. Nine headlamps roaming in different directions made shadows dance on the walls. Ahead was a tunnel and the booming noise of a waterfall or rapids, above us only a bit of diffuse light. Standing there it was easy to understand why the Maori felt the caves taboo, why they went in only as far as natural light allowed.
We followed Stu and Nic through a short tunnel and onto a ledge high above the river. The only way across was a "flying fox" or zip cord, a block and pulley that rolled on a 50-foot cable leading to a lower ledge. One by one we zipped down the cord, each giving a distinctive, involuntary yowl as he shot at a 30-degree angle into the blackness. I don't remember if I closed my eyes, because midway I had another, split-second panic: What's going to stop me at the other end? The answer came quickly. I suddenly stopped on my own in midair, as my weight stretched the cable flat. But my momentum yo-yoed me roughly forward, then back, until Stu flipped his lamp on and caught me.
We finally shed our harnesses, and Stu and Nic passed out inner tubes. The river here, wide and deep, had almost no current (making it clear that Black Water Rafting involves no white water at all). "There are two ways to get in," Stu said. "You can walk down," and he pointed to some stone stairs, "or you can go the easy way." Then, sitting on his tube, he turned around and leaped off the ledge, splatting into an easy landing 10 feet below.
I went first, and on impact I bounced off the tube and went under, getting a sedimenty noseful and briefly losing my helmet. The water was cold, Northern California ocean cold. It flooded under my wet suit at the neck, trickled to my waist.
We hand-paddled our tubes a short distance into shallow water, then carried them. There above us the first few, scattered worms sparkled like speckles of quartz. Stu summoned us to a head-high overhang along a wall. Under it was a cluster of brown, wispy threads, each about a foot long. "Glowworm fishing lines," Stu said. He explained how a larva secretes several lines, and covers them with a sticky chemical that paralyzes prey such as mayflies. It reels in the catch and then either sucks the juices out or eats the entire body. We looked closer and saw the brown larva, about the size of a matchhead.
"Actually," Stu said, "they're really just maggots. But if we called these the 'glow maggot caves' nobody would come."
Walking and swimming, we made our way about 200 yards downriver. The glowworms, their light dimmed by ours, had grown in number to sprinkles of glitter. We finally stopped under a high vault where water fell from the ceiling like rain. Beyond our lamp beams the huge black back of the cave continued.
Here we readied for the glowworm "parade." Sitting on our tubes, each rider's feet tucked under the armpits of the person in front, we formed a chain. Stu stood in front, and told us to turn off our lamps. Then--whack!--in the pitch black there was a startling slap on the water. (Later Stu said he did this with the bag of equipment he was carrying: Sound waves vibrate the fishing lines, and the worms believe insects are near and glow brighter.)
Above us, thousands of pea-size dots of light now grew in intensity. The pale aqua-blue light seemed to radiate, and reflected off the water like moonlight. No one made a sound. Slowly towed by Stu, we drifted beneath constellations low on the walls, and a long, Milky Way-like streak on the ceiling. Some blue dots were larger, glowed more brightly, than others. But each was distinct, because each worm needs its own feeding territory. Between them there was only absolute black. This deep black and the different intensities created a powerful illusion of three-dimensionality, so that I had the sensation I wasn't just looking at the night sky, I was moving through it. I lost track of time. I wanted to keep going, keep drifting.
The glowworm galaxy finally tapered, then ended. We flipped our lights on to a reality check: We were 150 feet underground and had to get back up. Strangely, I hadn't thought about that. Nobody had said anything about rappelling up a hole. The basic plan, Stu said, was simply to follow the river out.
We waded through a lot of water, squeezing one at a time on our bellies through a tight passage--only to find ourselves in a small chamber that had a waterfall crashing down on us. Again one at a time, Stu and Nic had to guide us foothold by foothold as we climbed up the waterfall, and found our way into another chamber. A saturated wet suit begins to feel like armor, and when we'd all made the climb we needed a breather. Somebody asked what was next.
Grinning, Stu said, "Let's just say what we're in right now is called the Passage of the Twin Falls." We groaned, but were soon climbing up another fall, to the "Labyrinth," where our passageway forked into five smaller tunnels. At the end of one was the proverbial light.
Crawling on hands and knees, we were midwifed by Nic out an opening, into the daylight. Coming head-first out of Mother Earth, it was impossible not to feel a little reborn. We were literally wet behind the ears. And after three hours in the cave, this world looked odd. The sun was shining. There was vegetation. We were all a little disoriented. We had had our encounter below with an extremely weird form of life. But now nothing looked weirder than the other people standing around in rubber boots and suits, blinking at the world, the lights on top of their heads glowing like faint stars.
The Waitomo Caves are a two-hour drive south from Auckland, New Zealand. United offers daily connecting service to Auckland from Dulles and is quoting a round-trip fare of $1,324. For information on area accommodations and the cave tours, contact the New Zealand Tourism Board, 1-800-388-5494, http://www.nztb.govt.nz.
Scott Carlson is a writer in Palo Alto, Calif.
© Copyright 1998 The Washington Post Company
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