Catanamatais Cave, Dominican Republic — The Pursuit for the Deepest Cave in the Caribbean Islands

I eagerly walk down the dense sloping patch of forest. The temperature drops as the moisture rises from the warm dry air of the mountainous Dominican Republic valley desert. Vines, slippery moist ground, and the occasional tree with spines are negotiated. All too soon, a dry mossy arroyo appears leading to a large black void that swallows water from two separate drainages.

From the research we conducted, there were two previous expeditions to Catanamatais Cave. Though known to locals for perhaps a century, Italian cavers first visited in 1988. Another group — possibly Italian, Dominican, and French — entered around 2005 and spent three days underground before turning around at a river. We found no written documentation of this expedition beyond word-of-mouth from locals.

There is a substantial entrance drop — approximately a 40-meter free-hang, then around 100-150 meters on a slippery 45-degree slope. The cave must be entered with single-rope-techniques. Wilson and Negrito, local residents from the nearby village, escorted us to the two cave entrances. The first was a depression sink leading to a large sloping void. The distant and long reverberating echoes from our voices were captured in this massive stadium entrance, making communication difficult.

We rigged the cave with over 50 bolts and hangers. Once at the bottom of the entrance sequence, the cave became warmer and humidity increased noticeably. We found a piton the Italians left from their expedition. Continuing deeper, the cave eventually branched into multiple sumps at the bottom.

The team located 4 sumps at the bottom of the cave. Jefferson and Steve conducted the dives. The second sump had clear water flowing into it, went to a depth of 2 meters, and was approximately 15 meters long — surfacing in ongoing passage with several in-feeders and a streamway that continued on. The air beyond the sump was not safe to breathe, limiting exploration to what could be tolerated while wearing a rebreather.

The results: the cave depth was not over 300 meters and the Italian map was inconclusive, missing passage, and inaccurate. The dry passages beyond the sumps were not habitable without lightweight breathing apparatuses — lighters would not light in the passages, and very small activities left the divers gasping for air. The 'impassable raging river' from local legend was in fact a sump. The low-air passage in Ceth's Gas Crevasse was the only passage seen by human eyes for the first time. Expedition members: Adam Haydock (co-leader), Ceth Parker, Gustavo Quesada, Jamie Goodwin, Jefferson Marchand, Lukas Eddy (co-leader), Rachael Crawford, Steve Lambert, Suhei Eddy, Zeb Lilly.