Exploring the Depths: Cave Diving in Mexico's Underworld

People say that we are born in the wrong era to be an explorer; too late to explore new lands, and too early to explore new planets. However, in the northern part of Mexico's Yucatan Peninsula lies the world’s longest underwater cave systems, a true playground for cave explorers, much of which remains largely unexplored.

Like many of you, I thought that this was just diving among wet rocks, that there’s not much to see, and that they are all the same. And nothing could be further from the truth. Over the last several years, I have been spending most of my vacations there, and after photographing over 280 cenotes so far, I’m still amazed at how they keep on surprising me with their different features, beauty and hidden secrets.

You can start by experiencing the Cenote caverns, where you don’t need more than an open water or deep open water certification. In them you will never be more than 60 linear meters (197 feet) to the surface and safety, and can get a feeling of the cave formations, light effects, haloclines and hydrogen sulfide clouds (yes clouds!). The classic Cenotes to start will include Dos Ojos, Car Wash (as open water) or Angelita, El Pit (as deeper dives, around 30 to 35m). The operators will provide you the lights and the only required skill is buoyancy control.

Many people will stay there enjoying the light entries of the 20 or 30 Cenote Caverns. Some others will be intrigued by those caves going further away from the exit and train to do cave diving. Progressing through training to be able to manage every situation that can appear, as you can not just go up to the surface, master navigation and gas management (intro and full cave), with time adding more tanks (Stage and Multi-stage), adding Dive Propulsion Vehicles and eventually a CCR. All to be able to reach areas that few or no-one has seen before!

The cave training is quite demanding, and the instructors have the obligation of only approving you if they consider you are truly ready, as your life will depend on it.

But if you do so, you will be rewarded with some of the most surreal and otherworldly experiences you can have on this planet! Unlike open sea diving, you may be diving in “filtered” water where the visibility may be as much as your light can reach, there’s no light besides the one you carry (and you carry many), but you will be diving in tunnels that may have a level of decoration that compete in beauty with the nicest gothic cathedrals from Europe, but in this case you can explore them in three dimensions.

Then you find the unexpected conditions that you don’t have anywhere else: the tannic acid pockets, of tannin from the tree bark that gets washed out into the cenotes when there are strong rains. The stronger the rainfall the stronger the color, from a green to yellow to a red when you have a high concentrations after heavy rains or a hurricane.

The hydrogen sulfide clouds, coming from the decomposed trees that fell into the cenote when it collapsed, and truly make you feel like you are flying on top of the clouds.

The haloclines, that in the caves may be perfectly defined undisturbed planes that will trick your brain to think that the lower salty substrate is actually the water, while the upper freshwater substrate will appear to you as air.

Then the amazing light shows close to the Cenotes (the collapses that connect the surface to the underground river systems) or finite light coming from a narrow opening and through the moving leaves of the jungle above.

I became obsessed with capturing this beauty. And most people will not believe that all these photographs are real, with no photoshop or coloring, just white video lights to bring light into the Underworld (as the Maya call it).

The more I dove, the more I discovered the beauty and secrets of these caves, uncovering unique fossils of extinct Megafauna, indications of the first Paleo Americans and Mayan artifacts preserved in their flooded tunnels. Collaborating with scientists to create photogrammetry models and 3D prints for them to study. These caves hold the data of the first human-made mass extinction, where the local fauna faced a new predator that hunted at a distance with stone tools and sophisticated social organization, ending with 75% of all genera of an already stressed megafauna population pushed to extinction. North American species like lions, camels, horses, gomphotheres (mastodons), giant sloths or sabretooth tigers got extinct and their fossils remain protected and hidden in the flooded caves.

Sadly, I also witnessed how we’re destroying this environment before it’s fully explored. The rapid urban expansion driven by tourism, cutting down the jungle, locking out cenotes into private properties, building housing with toilets draining directly into the soil or inside the cave, with pig farms and agriculture fertilizer polluting the very water they rely on. With developments like the Maya Train collapsing or destroying caves, along with failed attempts to enlarge the open water to attract snorkeling disrupting their natural flow, are all destroying this incredible natural wonder.

Seeing this instilled in me a deep sense of responsibility. The phrase “You will only protect what you love, and love what you know” resonates with me, especially when I realize that the landowners above the largest flooded cave systems in the world, and which sustain life in this ecosystem, are completely unaware of what lies beneath their feet.

That’s why I created the book, Light in the Underworld. As my attempt to make you fall in love with the Maya Aquifer, and hopefully recruit you to help protect this environment as well. The book tells the fascinating story of the aquifer’s formation, showcasing the immense variety of experiences you can find within, through photos I took in over 250 cenotes, and revealing its secrets. I’ve employed a wide range of photography and lighting techniques, Using mostly off-camera lighting, to diffusers, High Dynamic Range (HDR), panoramas, long exposures, light painting, infrared, or drones.

Transitioning from cave or open-water diving to cave photography presents a whole new set of challenges. In the pitch-black overhead environment of a cave, filled with delicate formations, it’s easy to become disoriented as you navigate the complex passages. Losing visual reference to your guide line or track of your depth can quickly escalate into a dangerous situation, especially when you’re managing two to four tanks and communicating with your dive buddy using light and hand signals with only one hand. Adding a camera and lighting gear into the mix significantly increases task loading, pushing your focus to the limit. This is why proper training, gradual skill progression, and a methodical approach are crucial—not only to protect the fragile cave environment but also to ensure your safety throughout the dive.

You’ll often hear that you should be able to operate your camera controls with your eyes closed— well, these are exactly the conditions you face in any cave dive.

My cave photography gear differs significantly from my open-water setup, not only to meet the photographic requirements but also to address the challenges of cave navigation. In a cave dive, you're often dealing with limited or no visibility, which makes managing both tasks and equipment far more complicated. Most of the time, you won’t have two hands free—or even one—especially during a zero-visibility exit where one hand must stay on the guide line and the other on your DPV. Balancing this while handling photography gear requires thoughtful preparation and careful management of your resources.

My photo gear is customized to be as small as possible and to fit my sidemount rig, with a small dome in a full-frame camera (due to the low light inside the cave, you need a big sensor to capture whatever light is available), integrated floats and no arms whatsoever. Clipping my slightly-negative camera to my butt-rings and leaving my hands free to navigate and communicate.

Another key to achieving these photos is a stable and trustworthy dive buddy. I have done over 400 cave dives with the same person: Nicolas Casella from CenoteXperience in Playa del Carmen. He’s the model in most of these images. Nearly all the images were captured on our first visit to a particular cenote or cave with no previous photo planning. Always following the rule of thirds: using one-third of our gas supply to penetrate and observe the cave, another third to exit while shooting the photos, and reserving the final third for emergencies in the unforgiving overhead environment. Our mutual understanding and quick communication in pitch-black conditions are crucial for that fast shooting approach, good composition and safety.

As underwater photographers, we’re privileged to witness the marvels of the natural world that few can access. With this privilege comes the responsibility to share our images with the public, raise awareness, and support conservation efforts. We are the visual storytellers that scientists and conservationists need as partners in protecting natural ecosystems. The stronger our images, the greater the chance that someone will stop and take notice. It’s crucial that we shift from a competitive mindset to a collaborative one, as time is not on our side.

The book Light in the Underworld, published by Rizzoli with a foreword by Dr. Alex Mustard and Paul Nicklen, was released on September 3rd, 2024 in the U.S., followed by a worldwide release. It is available on Amazon, Rizzoli, and other major retailers.

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