In role-playing game terms, I acquired the skills of sidemount scuba diving and cavern diving. A fish may be able Ito extract oxygen from water, and a seal, whale, or turtle may efficiently use the air they take in at the surface, but humans lack these natural adaptations. Fortunately, I am a tool-using mammal, and I have learned to scuba dive.
Diving in caverns requires an entirely new skill set. In open water, if something goes wrong, you simply surface and breathe again. In an underwater cave or cavern, air may be too far away to reach in time. Any pockets of air in the caves may contain methane, hydrogen sulfide, carbon dioxide, carbon monoxide, or other toxins, making them unreliable for breathing.
Cave diving is built on redundancies. Tanks—at least two. Regulators—at least two. Lights—five might be enough. If learning multiple systems wasn’t enough, everything must be streamlined to avoid snagging on rocks or formations.
As a newer diver, I had only just gotten comfortable with a single tank and a basic backup system. I was proud of my underwater light, which works at depths of 135 feet. Luckily, Kris, a veterinarian and fellow diver, connected me with an excellent instructor. Craig from Tulum Diving Center was incredibly patient. The buoyancy control device (BCD) for sidemount is much slimmer, and the buttons, gauges, and vent releases are in slightly different places. Even on my final training dive, I occasionally found myself resting among the stalactites while fumbling for my release valve. Meanwhile, the few fish I encountered in the caves navigated the different depths with ease.
I also never quite mastered the frog kick. My instructor glided effortlessly ahead while I attempted a few kicks and promptly lost all momentum. Craig kindly suggested that my knee might improve with time, but I suspect that’s only part of the issue.
To access the caverns, we entered through cenotes—natural sinkholes. The Yucatán Peninsula contains thousands of freshwater caves and about 750 miles of mapped cave and cavern systems. Cenotes are part of an extensive underground river network formed during the Ice Age when sea levels were lower. Rainwater gradually dissolved the porous limestone, creating vast cave systems. Over time, sections of the caves collapsed, forming open-air or partially enclosed cenotes.
The first cenote we visited had crystal-clear water, courting sailfin mollies, a school of black mollies stretching eight feet long, turtles, and a small crocodile resting in the reeds. In another, I looked up from buoyancy practice and forgot to breathe when I found myself face-to-mask with a school of wild guppies. Each cenote seemed to have its own variety of fish. I wasn’t lucky enough to spot any blind cave fish or freshwater shrimp, but we did surface into a cenote with several bats. (I love bats!)
From a scientific perspective, I was captivated by the speleothems—stalactites, stalagmites, and flowstone formations formed over thousands of years. Where saltwater and freshwater met, the halocline created a shimmering visual effect.
The ancient Maya considered cenotes portals to the underworld (Xibalba) and vital sources of freshwater. Some were used for rituals and offerings. Many cenotes contain Mayan artifacts and prehistoric remains, providing insight into ancient cultures and extinct species.
Every cenote we visited had undergone extensive cleanup efforts by its owners to remove pollution. Often, we were required to shower before entering the water to prevent contamination.
Over the course of the week, my skills improved. I wouldn’t say I effortlessly glided through the cave formations, but I was much better on my last day than on my first. The warm sun was a welcome change after shivering in Belize a few months ago. Since I only dove, ate, and slept, I also managed to catch up on much-needed rest. In fact, on the first day, I skipped dinner entirely—just had a jerky strip and went straight to sleep while Kris and Will went out to eat.
Above all, stepping out of my usual environment and learning something completely new was refreshing. I firmly believe that everyone should challenge themselves with a new skill unrelated to their job. It sharpens the mind, shifts perspectives, and leaves lasting memories—like the sight of cave formations and schools of wild mollies and guppies, which will stay vivid in my mind for a long time.
Back home, I had the opportunity to share my newfound knowledge with a group of gifted and talented 5th graders. I taught them about cenotes and cave diving, explaining the unique challenges divers face. For their exercise, I blindfolded them and had them follow a cavern line out of the building, simulating what it’s like to navigate in the dark with only a guide rope. It was a fun and educational experience, giving them a small taste of the problem-solving and teamwork required in cave diving.
Kris and Will will be going back in the fall for the second part of their cave diving. I might go with them. I don’t think I need to do cave training. Cavern and sidemount diving already offer plenty of adventure without the full cave commitment. It’ll be great to explore more cenotes and refine skills without the pressure of additional certifications! After all, as a tool using mammal, I now have new tools, I can use.