Robbie Schmittner by Ellen Cuylaerts

A life of exploration: Diving the caves of the Yucatan Peninsula

Robbie Schmittner is a passionate protector of the Grand Maya Aquifer. He connected two cave systems of the Yucatan Peninsula, making it the biggest flooded cave system and the second biggest worldwide. He advocates for the importance of clean water for communities. He is currently working to connect a third system and, after that, he will explore the Holbox fracture.

1. Robbie, you were born in Germany, but known as one of the most expert cave divers of Mexico’s Yucatan Peninsula of the last decades, how did this happen? When did you fall in love with this underwater world that sunlight cannot reach? 


In 1996, I visited my diving instructor, Gunnar Wagner in Tulum, Mexico. He and his Mexican wife Lina had moved there from Germany to open a dive center. As I had worked as a dive master at their former center in Germany and we had become true friends, I had the urge to follow them and see with my own eyes where they had found their new home.

Gunnar had become a cave diving instructor with the NACD (National Association of Cave Diving) by the time I got there to visit them. He told me: "You must do a cave diving course. It is the best thing to do on the planet and you will just love it”.

He was right! From the very first dive, I was mesmerized by the beauty of the dripstone formations, the clear water which makes you believe you are flying through this amazing scenery and the seemingly endless underground passages. Every time we had to turn around to get back to the exit, the slumbering explorer inside me wished to go deeper into the alluring darkness.

Unfortunately, my vacation was soon over and I had to go back to Germany. Still, I was hooked.

It took me two years until I was able to go back to Mexico for more cave diving, but during these two years, not a day went by that I was not mentally flying to the caves of Tulum.

The second time, I wanted to stay longer. I took a half-year break from my job as a lumberjack and flew back to Gunnar and Lina’s dive center. I started working for them as instructor, guide, tank filler, mechanic, painter, carpenter and dog-sitter. I did not care what I needed to do, I was just happy that I could dive the caves!

On day, Gunnar’s landlord, Don Cupertino Maas came to see us because he had several untouched cenotes on his property and he asked if we would be interested in exploring them. The very next day, Gunnar and I were running a guideline into our first virgin cave system, which we called Tux Kupaxa (playground).

Tux Kupaxa is still one of the most stunning cave systems found in the area and it ranks number three on “the longest water filled caves of the world” list.

Furthermore, another landowner, Don Roberto Caanche, came to see us with a similar proposal. We called his cave Dos Pisos and it was just as beautiful and breathtaking as Tux Kupaxa.

Exploration became a daily adventure: we built up our first camp and I stayed an entire month in the jungle. Needless to say, I was in cave heaven, addicted to the unknown.

The day I should have gone back to my ordinary life, I called my boss and resigned. With a heavier heart, I called my mother and told her that I would stay in Mexico, at least for another six months.

Twenty-one years later, the caves are still my passion.

Quintana Roo, Mexico, where I live and work since my arrival, has the highest density of cave systems in the world. By now, over 1,500 km (around 945 miles) are reported to the Caribbean state. This tremendous amount of passageways is divided into over 380 different systems. Some are small, some are real giants. The four longest underwater caves of the world are all sitting next to each other around the town of Tulum.

Robbie Schmittner by Richard Schmittner
Robbie Schmittner photographed by Richard Schmittner. © Richard Schmittner


2. As the exploration director of GAM (Great Maya Aquifer Project), you connected Sac Actun (previous 263 km) and Dos Ojos (previous 84 km) leading to the world longest underwater cave (2018). Your goal is now to connect to Ox Bel Ha (another 270 km). Why is this important to you and why are the proven connections important for all of us?  


For me, it is important because I had this dream, idea, premonition, if you will, since the first Tux Kupaxa expedition. Gunnar Wagner and I were swinging in our hammocks, by the campfire, high on our exploration success and on a glass of red wine. We were dreaming about the possibility that Tux Kubaxa would connect to Dos Ojos, and Dos Ojos to Nohoch Nai Chich, and this system to Sac Actun all the way down to the town of Tulum. Even though we were kidding about it at the time, both of us had the wish and dread this could become real one day.

Another time, I was out in the jungle with one of my role models, Jim Coke, the first cave explorer in Tulum – who is still is the director of the QRSS (Quintana Roo Speleological Survey). We were sitting on a fallen tree right in between Sac Actun and Nohoch Nai Chich, sharpening our machetes. I told him I would start to search for the connection in between the two systems. He laughed at the idea and asked, "What are you smoking? Can I have some?"

Even Bil Phillips, my mentor and true friend was skeptical and grumbled, "Other have tried that before".

If Sac Actun is now the longest water filled cave in the world is because I never lost faith, I believed that one day it would happen, as some of my companions did for a 14-year long, challenging journey.

For me, it is personal affirmation. The connection to Ox Bel Ha cave is just the next, logical step.

Apart from my personal challenge, this connection is important for all of us because Sac Actun will be, after the link has been found, the longest cave system in the world, dry or water filled.

If this connection will be established, the eyes of the world will be on us and we will get the chance to draw public attention on how important this aquifer is and ask for a better protection of it.

Sac Actun, the surrounding cave systems and even the rock in which the caves are embedded hold a huge treasure: an unimaginable amount of pristine freshwater. 

In the near future, unpolluted freshwater will be a very rare and precious resource. 

Today, however, this water is contaminated as a consequence of unregulated mass tourism and missing infrastructure. The water inside the cave systems allows contaminants to spread fast and to reach all different ecosystems on the peninsula: cenotes, mangrove forests and coral reefs.


Tulum cave system. Map by Robbie Schmittner.

3. Most of your preparation work is in the jungle, on other people’s land. The Yucatan peninsula inhabitants are a mix from different descents but mainly Mayan. How do they feel about you enter the world of Xibalba (Mayan mythical underworld)? How do you get landowners to agree with you having access?  


Indigenous of the Yucatan peninsula are descendants of the Maya, but huge parts of "cave land" have been sold to people from other parts of Mexico and foreigners.

In the past, it was easier to talk to land owners and get permission to explore their cenotes, but now it is becoming more and more difficult, because landowners have different interests. Properties are mainly bought as an investment and turned into building land. Many landowners prefer not to know about caves underneath their property to ensure construction.

Robbie Schmittner by Ellen Cuylaerts
Robbie Schmittner with the Explorers Club flag on the Vanilla Sky Expedition, 2019. © Ellen Cuylaerts


4. Is the rise in cave diving tourism and exploration important for the locals? How can visitors give back to the community?


More and more tourists come to dive the cenotes. Cavern and cave divers often support the community, as they dive and stay at local businesses, instead of all-inclusive hotel complexes, which are mainly run by foreign companies.


5. What does water mean to you?


Water is life! Life began in the water; our bodies are 70 percent water. We need water every day to survive. It is insane that we do not take better care of our resources.

Water is my element. It is where I feel most well, submerged.

We need to stop using our rivers as natural sewage systems.

We need to stop using our ocean as a garbage dump.

We need to stop industrial fishing.

We need to stop the production of plastic.

We need to stop global warming.

We need to stop drilling for oil at sea.

We need to stop human ignorance (e.g. shark finning and whaling).

We have to rethink, and we have to take action, or there might be no ocean for the next generations.


(Interview by Ellen Cuylaerts. Cover image by Ellen Cuylaerts). 

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