April 1: Waitomo

Previously: March 31

Today was to be a full day of caving: dry (for cave values of dry) in the morning, then wet in the afternoon so we could return home damp and exhausted to a warm shower.

Morning was hosted by our guide “Hop” from the Spellbound company, and the goal was specifically to see glow worms. Glow worms are larval flies (technically, “maggots”, but as Hop and everyone else who described the worms during the course of the day noted, “maggot” is one of those words that you just can’t put a positive spin on). The worms are tiny—about as long as a thumbnail and thin like spaghetti—and spend about 9 months attached to the ceiling of a cave with an expanse of roof and flowing water, dozing in a silken hammock. From the hammock, they drop a mess of sticky vertical threads up to about 6 inches long that dangle in the breeze, trolling for flying insects. Even at a significant distance into glow-worm caves, the flowing water brings in many larvae, which eventually become flying adults. To fool those insects into flying into the strands, the worms emit a bright blue glow that resembles the sky, and in so doing, trick insects into flying towards the light. Once caught in the dangling threads, the insects are injected with a digestive fluid that turns them into reservoirs of nutrients for the worms to slurp up at their leisure. the worms may consume as little as 5 insects during their short lives before pupating and emerging to mate and start the next generation.

Both of the Spellbound caves are what I call “tame” caves, since they’re easily walkable, with little or no walking bent over beneath a low roof, no crawling, and usually with a level footpath established to make walking even easier. That’s okay, since the goal of the exercise is not exercise, but rather a chance to see the glow worms. The first cave was a relaxing stroll to a point where the glow worms concentrated. Then out go the lights, and the only illumination that remains is that produced by the worms. It’s lovely, but as this was a relatively dry cave, with little flowing water, the glow worm density wasn’t very high. Once we emerged, we had a hot chocolate and biscuits break before moving on. In the stream beside our rest stop, there was a honking great eel—3 to 4 feet long. One of the guys on the tour was persuaded to touch it, and it let him. He called it the “slimiest thing I’ve ever touched”.

The second cave was extraordinary, as it had a much larger river and more interesting topography. To get to the heart of the colony, Hop embarked us all in a raft, then had us turn out our lights so he could haul us, hand over hand, along a rope that stretched from the dock to a small waterfall that marked the end of the tour. It’s hard to estimate distances, but I’d say around 30 m in total (about 100 feet). We spent a good 20 minutes moving slowly back and forth along the rope to see all parts of the cave. The glow worms were so densely packed it was like sitting beneath the stars on an unusually clear night. And the light was bright enough that after 5 to 10 minutes, you could see the 3D structure of the roof and walls, despite the absence of any artificial light or daylight. You could even see faces in enough detail to recognize people. Beautiful. It's clear why they call the tour spellbinding.

From there, we transferred to Waitomo Adventures, for 4 hours of “tubing” (i.e. floating through a wilder cave system in inner tubes). I’d hoped originally that we’d be rafting, and thus stay mostly dry, but in the end was very glad we’d gone the wet route of tubing. Much more walking and exploration and much more strenuous than I'd expected from the brochure. Our guides, Charlie (a young British woman who’d immigrated several years ago) and Joel (a native kiwi), kitted us out efficiently in wet suits: a bottom set of overalls that rose from shins to mid-chest and a top that overlapped the bottom. “Wellies” (rubber boots) completed the bottom of the kit, and helmets equipped with headlamps completed the top. The wet suits were special thick ones designed to protect us from hypothermia, and fit like I imagine a fighter pilot’s gee suit fits: tight enough that every movement required significant effort to stretch the rubber and let your limbs move, and enough to noticeably impede breathing. Took a bit of getting used to before we could walk semi-normally.

Our tour guides were extremely safety conscious throughout the tour, starting with a medical questionnaire to ensure that they’d be aware of any potential problems we had, and a careful reminder before departure to bring any meds that we needed. We started the tour with a 10-minute walk to the entry point, which was sweaty given the thick insulation provided by the wet suits. I mostly removed my top and helmet to avoid overheating during the walk. At the start of the cave, we descended a 7-m (25-foot) ladder leading into the depths. Further evidence of a concern for safety involved tying a rope around our chest so they could belay us as we descended. Nobody slipped or fell, but it was a reassuring touch.

Right at the bottom of the ladder was a depth gauge that showed the water level; if the water rose to as little as 40 cm above the floor at this point, they wouldn’t enter the caves and would cancel the trip, because the caves descend quite a ways, and by the bottom of that descent, deeper water at the start would mean that the water reached the ceiling at some points deeper in the cave.
Proof that this was not a tame cave arrived right at the start, at a rock formation they called “the claustrophobia test”. Joel perched atop the rocks and asked us to squirm through a narrow passage beneath them. It seemed likely that we could have gone over the top more easily than through it, but I suspect this was both a reality check to determine whether anyone had lied about not being claustrophobic and a chance for the guides to entertain themselves at our expense. Probably more the former, as there were several other tight passages later in the tour with no alternative routes that would have been awkward for anyone who feared close quarters. The test passage wasn’t dangerously tight, but I’m big enough that I had to reposition my body and scrape my wet suit past a couple obstacles to get through.

The rest of the cave was pretty much natural, apart from things like guide ropes that were helpful in some places. The floor was rough and uneven, requiring careful foot placement and often required leaning on or holding the wall for support. The space ranged from large open chambers to passages smaller than a doorway and a few quite tight squeezes to get through. Myriad rock formations, requiring much pausing to view the rocks that had been sculpted by both the millennia-long dripping of calcium-bearing water, producing stalagmites and stalactites, and ongoing sculpting by flowing water, producing sinuous curves and occasionally, narrow and blade-like formations. Endleslys variable, and endlessly fascinating.

Speaking of water, the flooded tubing sections weren’t the only place we got wet. Large stretches of the cave were filled with deep water; sometimes it descended slowly to its maximum depth, and sometimes you stepped into water of unknown depth. We quickly and repeatedly filled our boots with water, and they remained filled throughout most the trip, meaning that in addition to the ongoing effort required to move against the resistance of the wetsuits, we also had to schlep a kilogram or two of water (a few pounds) in our boots for most of the walk. In many places, the water rose chest-deep or was even too deep to stand in, requiring us to swim across. The wetsuits provide flotation equivalent to a life jacket, and when you swim, you only use your arms because moving your feet too much risks losing your boots. The water was cold, particularly when injudicious flexing opened a brief gap between the top and bottom and water leaked in, but the wet suits did their job and kept us warm. One very skinny woman had such long arms and legs that she stuck out from every opening of her suite, and was feeling quite a chill; our guides produced an additional layer that helped warm her up again.

In a few places we turned out our lights, either to feel what complete darkness was like or to better see the glow worms. The Spellbound glow worms were more abundant, but these ones still put on an amazing display. Particularly when we were floating on our backs down flooded passageways in tubes so we could gaze up at the ceiling without worrying about tripping over something or craning our necks uncomfortably.

Midway through the trip we stopped for a hot orange drink and chocolate, which was very pleasant and warming. One of those nice little bits of attention to detail that really makes a tour effective.

After about 3 and a bit hours of trekking through the cave, we finally emerged at the bottom of a deep sinkhole, and clambered out along a trail that passed through a small patch of forest. In total, we’d traveled about 900 m (3000 feet), at a depth ranging up to 13 or so m (about 40 feet) below the surface. We ended the tour with a short hike back to the equipment shed where we'd started the tour, forceful extraction from our wetsuits with help from our guides (it's a difficult task to peel off the tight rubber on one’s own), then a warm shower (though no soap or shampoo) and change into dry clothing.

We werent allowed to bring cameras, as the risk of delays, injury, or damage to the camera was too high. Instead, Charlie and Joel took many pictures, which they’ll send to us and we’ll hopefully post eventually. (We're still having trouble with unreliable and slow Internet access, so uploading photos hasn't been possible.)

After Charlie and Joel dropped us off at the parking lot, we decided we were weary enough that if we went back to the hostel, we’d never make it back out again for dinner. So on the way home, we stopped off at Hu Hu for our second dinner there. I had yummy parmesan gnocchi with tomato sauce, and Shoshanna had pork hock with kumara mash and apple syrup. Same beers as the previous night, equally good, though we ended with a shared butterscotch sundae garnished with homemade marshmallows instead of repeating the warm brownie.

Home to the hostel for a shower, footrub, and preliminary packing for the following day.

Next installment: April 2