Exploring Mexico’s Intricate Cave Systems — OX BEL HA
What is a cave system?
When we refer to a cave system we are describing a water filled cave with more than one entrance. Here in Mexico, cenotes are often connected through cave passages, and single entry caves are more of a rarity. In other parts of the world single entry caves are more common, where there is only one way in and one way out – through the cave entrance you came in! In contrast, the Mexican cave systems are known for their complexity as there could be multiple ways to get back to your entrance, or the choice to traverse to another entrance cenote and exit there. This brings me to my next point about the complexity of navigation in Mexican caves. While the system arrows may point to an entrance, this may not be the entrance where you began your dive. With so many suitable cenotes for diving, this article will begin to explore one of the many cave systems I have been diving here in Mexico.
Cave divers’ paradise
In the stretch of coast from Cancun to Tulum (and just south) there are more than 1680 kilometers of explored underwater cave. This does not count the 360 kilometers of reported dry caves! And this number, 1680 kilometers, comes from the Quintana Roo Speleological Survey (QRSS), whose data is made up of the survey data reported by explorers since 1990. There are certainly more unreported or unsurveyed cave lines in the area, and estimates put the current amount of explored cave in excess of 2000 kilometers! So we have a WHOLE LOT of diveable caves here. Let us dive in and look at some of the biggest cave systems in the area.
The Ox Bel Ha Cave System
The biggest cave system, in terms of length, is the giant Ox Bel Ha (OBH) cave system. This mega labyrinth of tunnels is reported to have over 500 kilometers of explored cave (there is a discrepancy in length between QRSS data from 2022, and a report from explorers from CINDAQ (El Centro Investigador del Sistema Acuífero de Quintana Roo)). The OBH system stretches from Tulum in the north to the Sian Kaan Biosphere in the south, and (mostly) from the 307 Highway down to the sea. As exploration continues it is sure to expand further! The ‘classic’ Ox Bel Ha area was centered around the three ‘rivers’ where water flowed through the cave passages to exit in the sea. Significant exploration began in 1998 when the Grupo de Exploración Ox Bel Ha (GEO) began to focus on these caves. Early exploration involved setting up base camps in the jungle and camping out while diving and exploring. Team members of GEO were: Bernd Birnbach, Steve Bogaerts, Fred Devos, Christophe Le Maillot, Sam Meacham, Bil Phillips, Daniel Riordan and Sabine Schnittger. Over time many other divers have contributed to exploration of the cave system and other cenotes (and cave systems) have been connected in.
Sistema Naranjal Cenotes
Many divers would be familiar with the caves Mayan Blue, Cristal and Jailhouse. If you have done any cave diver training in Mexico you might have visited one of these cenotes. These caves each have their own beautiful cartographic map made by Jim Coke in the 1990s (with exploration done by various divers in the 1980s and 1990s). These are popular dive sites, easy to access with a huge variety of dives to be done and extensive cave passages to see. Whether you want to just dive with two tanks, or do a multistage scooter dive, these sites have got you covered! Big, dark tannic stained freshwater tunnels, and stunning saltwater sections give dives in these locations very different looks at the same dive site. With some other cenote entrances, such as Cenote of the Sun, these caves made up Sistema Naranjal. These caves are significant archeological sites, as three human skeletons have been found predating the flooding of the caves at the end of the last ice age. In 2011 Steve Bogaerts and Bil Phillips connected Naranjal with OBH through Jailhouse. This was a massive contribution to the overall length of OBH, with Naranjal extending into the jungle to the northwest of the highway.
Chuup Itch or Corazon del Paraiso
Bil Phillips and Steve Bogaerts originally explored this cenote in 2001-2003. Many of their original markers can be seen on the main lines of the cenote. They connected it with a section of Ox Bel Ha. Back in 2001, there was no road into the cenote, so explorers and their helpers (“sherpas”) carried in everything needed for their dives from the 307 highway. The original explorations were a part of an official Explorers Club Flag Expedition. In 2015-2016 Bil Phillips returned and conducted further explorations with Dan Lins in the upstream section. Since then the cenote has been opened up with a nice road and facilities, and it is a much easier place to get to than in the original explorations. Similar to the Naranjal cenotes, Corazon has a dark, tannic stained freshwater section, and a halocline at 14 meters below which is pure white limestone. From the cenote, divers can dive either upstream or downstream and see a nice variety of formations and different sized passages. Since the cave was opened to the public a few divers have continued the exploration, finding many more kilometers of cave.
Yax Chen
Cenote Yax Chen was first explored by Gary and Kay Walten in the early 1990s. They did a lot of exploration in the area, and unusually most of it was from the same cenote. Yax Chen is a huge lagoon in the mangroves, on the other side of the beach road, making it just a stone’s throw from the Caribbean Sea. There are outlets of the cave into the sea. Most of the cave extends off to the northeast, heading inland under swamp and mangroves. The principal cave tunnels are massive subway sized power passages, stained dark by the tannins being washed into the cave from the mangroves above. The cave was connected to Ox Bel Ha and in recent years has seen further exploration from teams of Global Underwater Explorer divers. This is a great one to dive with DPVs to get further along and see some of the other cenotes that are only accessible from underwater.
Regina Area
Cenote Regina was named after the landowners daughter when explorers began diving and exploring this cenote. Unfortunately the principal entrance is now closed to divers, but two other (close) entrances grant divers access to this amazing section of cave. The cave was explored by various divers over the years, Alex and Torsten Kampe, Robbie Schmittner, Nadia Berni and David Seif all contributed, as well as divers from Mexico Cave Exploration Project (MCEP). The cave here drops to a deeper, thirty meter level, making it unusually deep for Mexico. This deep saltwater section is an amazing dive, with cool looking decorations, as well as very different coloration of the floors, walls and ceilings. Recent exploration in 2019-2020 by a team of divers from ProTec Dive Centers led to the connection of this system with OBH.
The cave systems of Mexico, particularly Ox Bel Ha, offer an unparalleled underwater wonderland for cave divers. Spanning over 500 kilometers of mapped passages and still growing, Ox Bel Ha stands as a testament to the dedication and skill of generations of explorers. The system’s complexity and beauty are mirrored in it’s many cenote entrances like Mayan Blue, Corazon del Paraiso, and Yax Chen, each with its unique history, features, and breathtaking formations. Beyond their allure as diving destinations, these caves hold significant archaeological and ecological importance, offering glimpses into ancient human activity and providing critical insights into the Yucatán’s aquifer systems. These intricate subterranean networks are not just marvels of natural architecture but also vital ecosystems and repositories of history.
All photos by Alvaro Herrero, Mekanphotography.