The Land Before Time
The limes tone caves of Indonesia’s West Timor are composed of millions of tiny sea creatures that lived eons ago
When exploring unknown caves in the jungles of Indonesia’s West Timor, you need patience — and a bit of luck.
Itfeels more like a show-and-tell at grade school than gearing up for a cave dive. Fifteen curious youngsters have gathered to watch me prepare to enter the West Timor cave known as Goa Oehani. The translator and guide passes me two side-mount tanks, fins, a mask, a helmet with primary light, and my huge camera rig. As I attach my cave-diving reel to my side-mount harness, the kids are watching intently, except for one small boy who takes a running jump to splash into the other end of the pool. With a quick wave goodbye to my spectators, I duck under the surface and follow a trail of laundry detergent packets and pieces of discarded clothing down the rocky slope. The entrance pool leads under a few boulders and down to a narrow restriction at about 20 feet deep. With a shake to settle my side mounts, I squeeze through and into the passage beyond. My dive light scans across chalky-white walls framing a deep-blue tunnel disappearing into the distance. After days of stalking the area and finding nothing but dead ends, Goa Oehani goes!
Exploratory cave diving is an absorbing hobby, and finding divable water is the last step in a very long process. Stories told by cave divers of rolling out mile after mile of new tunnel are only the tip of the iceberg — underpinning that success is often years of planning, effort and usually several failed attempts.
A few years ago, while studying a small map that depicted the distribution of limestone across the globe — most of the world’s caves are formed in porous limestone — I noticed a bright spot in Indonesia. That was intriguing; I was under the impression that the islands of Indonesia were mostly volcanic and unlikely to host caves. Indonesia is close to my home in Melbourne, Australia, and much easier to get to than flying halfway around the world to dive in Europe or the Americas. By that point I had dived the common — and some very uncommon — cavediving spots in Australia. My latest local project, a cave called Elk River in Victoria, Australia, involved long muddy crawls and cold water. Tropical destinations with unexplored underwater caves sounded very tempting.
My online research led me to the local reef- diving outfit, Dive Kupang Dive. Occasionally, it took divers to an inland swimming hole. The water was said to be crystal- clear, and the swimming hole continued into a tunnel underneath the rock. The single photo online was dark but clear enough to see the cave structure. It was time to plan a reconnaissance trip to the island of Timor, which lies at the eastern end of Indonesia’s Lesser Sunda Islands.
2013: Virgin Goa
The first trip to West Timor in September 2013 was hot, exhausting and 80 percent unsuccessful. Supported by Dive Kupang Dive, we dived the swimming-hole cave on the first
day. After delighting in water as clear as Tanqueray gin, an inspection of the air chamber at the end of the short underwater tunnel didn’t look promising for further tunnels. We needed another entrance, and the hunt was on.
We spent a week being driven around on bumpy dirt roads through the dry, scrubby landscape, inspecting potential caves that were tiny, completely dry or more rumor than reality.
Over the course of the trip we checked close to 80 prospects, making exploratory swims. We finally returned to one pool that we identified at the start of the week as having some potential — the local laundry spot near the village of Oehani. The water’s edge of Goa Oehani ( goa translates to “cave” in Indonesia’s Bahasa language) was littered with single-use detergent packets and discarded clothes. Surrounded by village kids, we made the last dive of the trip. Eight hours later, we emerged from the water, triumphant after swimming down half a mile of huge blue passage and crossing two large air chambers. The bait had been set, and I was completely hooked on Timorese exploration.
In 2014, I returned with a larger team, and again in 2015 and 2016. On these four expeditions, the geology of Timor has slowly given up its secrets to us. The ongoing hard work to explore the caves has been rewarded with huge tunnels and delicate cave formations never seen by another person.
2014: Umbu’s Shaft
The limestone in Timor is young and soft. Usually, limestone is composed of millions of tiny sea creatures from eons ago. Their skeletons on the seabed have compressed into rock. In Timor, they’re not very compressed. As we swam through tunnels it was possible to see brain corals, oysters and other shellfish
formations in the walls. The salt water from the Timor Sea permeates through the bedrock. Salt water is denser than fresh, so the seawater sits under the freshwater layer. Over millions of years, the mix of these two layers started a reaction that dissolved the limestone and created caves.
The downside of soft limestone is that large tunnels often lead to large rock piles that completely block forward progress. Nowhere was this more evident than in a cave discovered by Umbu, our translator. Umbu normally works as a divemaster for Dive Kupang Dive, and his English is excellent. Lacking formal cave-diving training meant he was unable to join us in the water, but his enthusiasm was channeled into a furious hunt for good diving prospects for our team.
The entrance to Umbu’s Shaft is a small borehole in a local family’s backyard. Discovering it on our second trip in the same area as Goa Oehani, our eight-member team immediately considered it an excellent prospect. Unlike other large rock-pile- collapse entrances we were able to walk down into, we needed rope ladders and climbing gear to access the main chamber. Creating an improvised rope ladder out of locally available marine rope and lengths of electrical conduit took most of an evening, but we succeeded in creating something that allowed us to explore.
The small opening to the outside world meant that the chamber below was like a sauna — an oppressive 104 degrees, with 100 percent humidity and not a whisper of air movement.
The main chamber of Umbu’s Shaft has two pools on opposite sides. We dived the large pool first, and it revealed hundreds of feet of tunnel. The passage started off large and gradually reduced in size before pinching out.
2015: Pushing the Boundary
When we returned the following year, we turned our attention to the tiny pool of water on the other side of Umbu’s main chamber. The tide was at full flow, and sitting by the side of the pool revealed water movement through the rocks. This seemed promising — the water must have been traveling through open space behind the fallen rocks to achieve that kind of flow.
We carefully moved a large floor boulder, which created a diver-size hole underneath. We drew straws to see who would dive first. Tim Muscat geared up, with the rest of us watching in the stifling heat. Waiting for a dive buddy to return from the initial exploratory dive is always nerve-racking. There’s a chance they’ll be back immediately, having found that the entrance doesn’t lead anywhere. But as time drags on, it becomes more likely that they are pushing out into new territory. A little while after that I start to get nervous … until bubbles echo up the wall and the beam from a dive light can be seen.
In this case, the small pool led Tim a short distance, only about 30 feet long and 3 feet deep. His return was delayed because he removed his tanks and investigated the air chamber on the far side. He reported that the exit pool had large boulders blocking the view but a short climb up through them revealed a huge air chamber — and two tempting blue pools.
Timor was living up to its reputation for rock piles, but unlike so many others that completely blocked our way, Umbu’s
Shaft gave us a pathway through. All of us — Steve Fordyce, Dave Bardi, Sandy Varin, Ryan Kaczkowski, Michelle Doolan, Craig Howell and me — geared up for a two-minute dive through and into the second air chamber.
This second air chamber had no direct access to the surface and had a saunalike feeling similar to the first. Sherpalike, we hauled our dive gear down the rope, across the main chamber, through the short dive and across the second air chamber, and drew straws again. Tim and Michelle were gone for nearly an hour, exploring the biggest pool yet. They returned triumphant with an empty reel. It seemed like we had finally cracked into the mother lode of West Timor’s cave diving.
We returned the following day to follow up on our success in the first pool, hoping for clear water in the second. It was finally my turn to dive. I dropped down the rope, across the chamber, through the short dive and across the second chamber, with camera and housing in tow, to the tanks and regs we had staged the day before. I dropped into water that was still slightly milky from yesterday’s exploration.
We followed the line laid the day before and tied a new reel into the end of it, with a big passage beckoning us on. The tunnel was more than 60 feet across and still going strong. But amazing highs were followed by devastating disappointment. A short distance later, we swam up a huge boulder pile and surfaced in yet another air chamber. This third chamber featured a steep wall of massive rocks heading up from the water. It was difficult to climb out, and there was little room to move around up on top. The tunnel forward was blocked.
While awaiting our return, Dave and Sandy checked the second pool of the second air chamber. They headed down the steep rock slope toward it, the first people ever to step there. As they moved, small rocks and rubble rolled down ahead of them and dropped into the water. It was enough to change the stunning blue pool to milky white and destroy the visibility, along with any chance of finding an underwater tunnel entrance below.
With both ways temporarily blocked, we were out of time to wait for the water to clear up. On that last diving day in 2015, we clambered out of Umbu’s Shaft late at night, already refining the list of objectives for the next trip.
2016: Into the Unknown
In 2016 we returned to West Timor and Umbu’s Shaft. The primary objective: access the pool at the bottom of the rubble slope, without disturbing the viz. That mission was accomplished, and the cave quickly gave up a reel’s worth of that familiar big blue tunnel along with the ecstatic joy of exploration. Once again I was able to take photos of divers reeling out into the unknown as we swam into places no person had seen before.
Exploring the Timorese caves taught me a great deal about persistence and patience. Checking prospect after prospect without becoming disillusioned rewarded me with the best dives of my life. Each year, we mapped the caves of West Timor, spidery lines indicating the subterranean maze, and unrolled more knotted string into never-before-seen tunnels. While these caves were difficult to find, challenging to access and hard to photograph, the effort truly paid off.