Cave
Cozumel Underground
We offer a short blast from the past, circa 1997, detailing some of the first cave dives on the island, and the people that helped put the Cozumel underground on the map.
by Michael Menduno

Please note that this story was written in 1997.
Cozumel, Mexico—While the race to stake-out the world’s longest underwater cave marches on beneath the Yucatan jungle, a handful of explorers have been quietly plumbing the depths of some of the most unique fresh-water caves in Mexico, less than an hour’s run away. The trouble is, no one believes that they’re there.
Thirty-nine year old financial consultant Jeff Bozanic has found it hard to convince others that there are caves in Cozumel. Over the years, Bozanic, who has been exploring the island’s cenotes for more than a decade, has learned to keep his mouth shut.
While attending an international cave diving workshop in Cozumel, Bozanic followed his instincts and shelled out fifty bucks for a jungle horseback ride to check out the mud-red cenote described on a hotel flier. Getting off at the sinkhole, Bozanic stripped to his briefs, strapped on the make-shift fifty that he cajoled the guide to carry, and slipped into the dark tannic water. Local Mayans thought it was only six feet deep. But they weren’t cave divers. Bozanic descended through the blackness for what seemed like minutes, broke out into clear water at 60 feet, and tied off his safety reel at the top of the large stalactite.

“I hit 120 to 130 feet on that first dive at Xcan Ha, and collected a shrimp and an amphipod,” recalls Bozanic. “The amazing thing was that when I got back and told others what I’d found, no one would believe me.” A hundred and twenty feet deep? At the time, the deepest Yucatan caves were less than sixty.


The year was 1987; five years before the term, “tech diver,” was even invented. The sixty- to seventy-odd speleo-brethren who attended the New Frontier, “Exploring The New Frontier” organized by the late Parker Turner, were jonesing to explore the gargantuan systems being discovered across the channel in the Yucatan—the new underground Mecca. Only a handful of cavers would ever know, or care, that the specimens that Bozanic had collected turned out to be two new species; the first of more than fifteen that he and his cohorts would discover on the island.
Bozanic and company put Cozumel cave diving on the map three years earlier when he noticed a fresh-water halocline while beach diving with his sister off Chankanaab park and followed it back to its source. Two months later, Bozanic and fellow speleo-phile Dennis Williams returned for a week to survey Cueva Quebrada.

“We found thousands of feet of line in the first four hundred feet of cave, if you can believe it—everything from monofilament to clothesline,” recalls Bozanic, who’s considered one of the greybeards in the field. His last dive at Quebrada, required three aluminum eighties in addition to his back-mounted doubles, and lasted almost five hours. Today Quebrada, is the longest of six major caves on the island, boasting nearly six miles of underwater passage.
On to Aerolito
Having road-rigged two sets of dual independent eighties, Yucatan explorer/instructor Steve Gerrard and I make our way past the four-foot high mound of refuse, empty cerveza bottles and a used pink condom—a local tribute to environmental awareness. Negotiating the slippery embankment, we slide into the emerald green cenote where our guide, Chuck Jones, is adjusting his head-lights. It’s the first time that either Gerrard or myself have cave dived in Cozumel.
We take turns leaning back in the 72° F water for a bubble-check. I’m fizzing—one of my DIN adapters is refusing to mate with the Dali-esque valve on my battered Cozumel renta-tank leaving a tell-tale bubble trail. Jones peels off an o-ring from his watch band, and proceeds to save my dive while launching into his briefing. You can tell he’s done this before.

Located near Caleta Marina, in the area slated for the ‘reef-eating’ cruise ship pier and more shopping malls, “Aerolito de Paradiso,” is one of the most “bio-active” caves on the island, with more than 20,000 feet of surveyed passage from thirty to over 100 feet deep. Like the nearby reef, its future is clouded by possible development.
Underground film-maker Wes Skiles was the first to map out the cave for a hydrology report in 1986. Five years later, Jones started swimming the system, and added nearly 3000 feet of line. Our goal today is to make the half-hour swim to the Dome Room, a huge water-filled chamber, 350 feet in diameter, eighty feet from ceiling to floor, about 1600 feet back in the cave. Bubbles in check, Jones finishes the briefing and we submerge.
Chuck Jones is a member of the Cozumel underground in good standing. A computer nerd by trade, diver by avocation, Jones first dived Cozumel in the seventies, and then moved to the island nine years ago. His friends thought he was nuts.
Like cave diving, making a living in the dive business is a matter of survival. Jones survived in order to feed his passion for virgin passage. This year, in response to cyber-island economics, Jones decided to go into business for himself, and put Cozumel on the net.
Like Bozanic, the forty-five-year-old Jones can attest to the unique hazards of Cozumel cave diving. Last summer, he and five other volunteers got caught in a Mexican cross-fire between the Federalies and local Institute for Nautical Anthropology and History (INAH) officials while recovering submerged Mayan pottery under the supervision of a museum archeologist.
The cenote was slated to be buried under a local housing project.
For their efforts, Jones spent four days in jail before the Mexican court determined that INAH hadn’t done the proper paperwork. Jones and the others were released only to be flamed on the net by state-side cavers who didn’t know the whole story. Retorts Jones, “Cave diving community is an oxymoron. I still do cave and cavern tours and teach, but these days I watch my back.”
Dome Room logged, Gerrard, Jones, and I finished debriefing over a three dollar dinner with sangria, at a neighborhood eatery. If the price didn’t give away the local nature of the establishment, the three brightly-painted young ladies of the night having their breakfast at the table next to us, did.
Jones recently got back from his first fly over the island paradise to scout out new cenotes. “Talk about information overload, I was bowled over. I had two cameras, one with a 70 mm lens, and couldn’t shoot film fast enough, reports Jones. “ All I can say is that there are a lot of cenotes on this island.” And no one even knows that they’re there.
Jones is emphatic, “We need more cave divers; it’s the only way to create the pressure to find more caves.”
And protect the ones that are there.
Return to main story: Laying Line in Cozumel
DIVE DEEPER
aquaCORPS Archives: The race to claim the world’s longest underwater cave was in full swing pitting two groups of Yucatan explorers against each other in Dos Nohoch No Dos Ojos You Are My Baby by Michael Menduno and Dean Mullaney

Michael Menduno/M2 is InDepth’s editor-in-chief and an award-winning journalist and technologist who has written about diving and diving technology for more than 30 years. He coined the term “technical diving.” His magazine “aquaCORPS: The Journal for Technical Diving” (1990-1996) helped usher tech diving into mainstream sports diving, and he produced the first tek.Conferences and Rebreather Forums 1.0 & 2.0. In addition to InDepth, Menduno serves as an editor/reporter for DAN Europe’s Alert Diver magazine, a contributing editor for X-Ray mag, and writes for DeeperBlue.com. He is on the board of the Historical Diving Society (USA), and a member of the Rebreather Training Council.
Cave
Madagascar Madness
Earlier this summer Jake Bulman and the Protec Team launched their 2023 expedition to Madagascar’s formidable Malazamanga cave known for massive tunnels, formations the size of buildings, and its unbelievable cobalt blue water. They then journeyed to Anjanamba, which despite enormous passageways, consistently turned into tight, restrictive spaces before opening up again. Having appeased the cave spirits and returned safely, Bulman offered up this account.

by Jake Bulman. Photos by Phillip Lehman. Lead image: (L2R) Jake Bulman, Patrick Widmann and Ryan Dart motoring through the first mega-room after Ryan’s Chamber, Malazamanga.
Deals made. Plans Laid
As I sat in the Paris airport working on my computer, Patrick Widman gestured to me to remove my headphones. He and Phillip Lehmann sat across from me and asked if I wanted to make a deal. Assuming I was walking into some kind of joke, I replied with a hesitant “Sure.” “Next summer you come with us to Madagascar, if you…“ “Yes! Deal, ” I answered before he finished explaining my end of the deal. It didn’t matter, the answer was yes. Patrick finished laying out his already agreed deal, headphones went back in and everybody went back to what they were doing, except for my thoughts, which went to “Holy Shit! I’m going exploring in Madagascar!”
Now nearly a year later in June 2023, we were back in Paris, this time packing all of the bags for the flight to Antananarivo (“Tana”), Madagascar’s capital city. When we got there we met up with Tsoa, who is the local contact, translator, organizer, and overall critical part of the team. Our bags headed to Toliara with the drivers while we spent the day doing some errands.
The next day was important to me, not because i turned 30, but it marked the end of a bet Patrick and I made in 2020, for which I had now won $100. The victory was short lived, however, as I spent that day stuck in my hotel room violently sick. Welcome to Madagascar!
After a short flight, overnight in Toliara, then an hour long boat ride along the coast, we reached Anakao Ocean Lodge. This place is a bit of a shock to the senses after traveling through the poverty stricken cities. Luxury in the middle of nowhere; it would be our basecamp for the trip. As Patrick and I posted a photo of the place, Phillip sarcastically mourned the loss of any “hardcore expedition” image people would imagine.
The next day we planned to meet up with the National Parks’ representatives, organize porters, transport all the equipment to the site, then get in the water and place all of the deco tanks and scooters we would need, and finally be out by dark to avoid being stranded overnight. This may seem overly ambitious, and it was, but is a good example of the overall approach of the project. Always go all in, no shortcuts or laziness, and if it was not possible in the end, no worries at all. The goal is to have fun with the group and do awesome stuff, which we always did.
”This is the most epic cave ever”
Phillip Lehmann on Malazamanga

Musing on Malazamanga
Malazamanga, a cave of indescribably massive tunnels, formations the size of buildings, and amazing blue water dominated the first part of the trip. We set up a little basecamp in the mouth of the cave, each of us with our own spaces to change, hang up our suits to dry, and change sorb each day. The entrance swim is a tediously frustrating one for rebreather divers: 20 minutes of low ceilings, bouncing from 20 m to 5 m/66 ft to 16 ft and back several times, never allowing space to sit “in trim”, and no flow to remove any of the inevitable silt that came from passing with multiple scooters, stages and divers.
However, once you reach Ryan’s Chamber, the first big room, you find a staging spot for leaving scooters and tanks for the following day, and a small tunnel leading to the real, intimidatingly massive, Malazamanga.
Patrick and I went to the deep section right away (45-50 m/138 to 164 ft) and spent three days trying to find the way on, while Phillip and Ryan Dart looked around the shallower parts of the cave (20-30 m/66-100 ft) for any leads that had not been checked. Patrick laid line while I surveyed behind him through a wide but low space that became swirling silt and clay by the third tie off. We reached a vertical shaft, Patrick asked me to hold and ran a line into a smaller tunnel below us that led to a restriction. In spaces like this where zero visibility is guaranteed, diver two will be pushing through restrictions blind, having no idea the shape or size of the space around them, which is a recipe for disaster, so I waited on the line for Patrick to return and started a timer.
As fifteen minutes showed on the timer, it started to feel like a long time. How long do I wait before doing something? Five more minutes rolled by, and my mind started to run… What if he has a problem? Does he need help? Memories of having to get somebody out of a similar space once before came to mind. But this time it was Patrick though, if he truly needed help it would be a serious situation. I decided to give him until 30 minutes from when he left, and then I would go in (slowly). With four minutes remaining, a glow appeared before Patrick explained that “it’s tight, but it goes.” It was a long wait that meant a bunch more deco, but this could be the way on.
The next day I was tasked with pushing the End Of Line (EOL) while he and Phillip looked elsewhere. After twisting, turning, removing tanks, and wondering if this was a good idea more than a few times, I pushed through a few ups and downs, but the cave unfortunately ended in a basement section at 52 m/170 ft. No going leads. Time to head home.

Breakthrough and Packing Techniques
Our daily routine started at 06:30 with a breakfast of bread, fruit, eggs, tea and espresso. We’d leave the garage at 07:00, meet the porters at the bottom of the hill in the national park and send the equipment with them. Phil would then educate us on the risks of breakthrough, importance of proper packing techniques, and the impact of dwell time. All of which are critical to making espresso.
After making espresso, the handpresso is put away, we hike the 30 minutes up the hill, get dressed, dive four to six hours, then head home. Back at the garage by 08:00 pm, fill tanks for an hour, eat dinner at 09:00 pm, and then sleep. All the while making jokes, sharing stories, talking about life, trying to blind each other with lights, and being shown the same photo of Rosie, Phillip’s pit bull, with a “look at this awesome photo” preceding the photo display by a few seconds.
All in all, going diving required some effort, not to mention the week of traveling with piles of luggage to get there, the week to get home, and all of the time spent organizing beforehand. In terms of “cost (time/money/effort) per hour underwater” it is some of the most expensive time I’ve ever spent underwater.

One day, after a significant amount of problem solving in the hot, muddy entrance tunnel of the cave, we finally got everything sorted and started doing checks. Halfway through, Phillip said, “I’m not into this. You guys go. Nobody is paying me to do this,” and started to remove his tanks. Considering the “cost per hour underwater,” I think many of us would go whether we wanted to or not, giving in to a sunk cost fallacy-like sense of commitment.
We reformed a plan for the two of us, a few angry birds levels were completed on the surface, and everybody went home excited to see the survey data. There is a lesson to be had here for many of us, about what is actually important and ignoring those perceived, often self-induced pressures to carry on even if it doesn’t actually make sense.
We scoured every corner of the section we were in, until a hole underneath a formation showed a large room on the other side. I tied in at ~40 m/~130 ft, headed down the slope to where floor met wall, removed my tank, locked the reel, threw it through the hole, and headed in. Once my torso passed the squeeze, still inverted in the water, I put my tank back on, grabbed the reel, and swam the direction that I remembered it went. I passed the cloud and made a tie off. Turn, tie off, into a bedding plane, tie off, big room, tie off, and stop.

The floor suddenly featured huge, wavy marks that everybody recognizes as signs of flow. A lot of it. Massive clay bricks fit together like tiles in the riverbed resembling floor. A promising development, I tied off and ducked my head under the lip of the ceiling. Instantly the ceiling met the clay bed and the cave ended. Water unfortunately doesn’t consider human size in its choice of direction. Back to the drawing board.
“Fuck it, let’s just see what happens”
Patrick Widmann
To Breathe or Not To Breathe
At the time, the furthest reaches of Malazamanga was an enormous collapse with no way beyond it except a few air domes. We were aware the air domes may not be breathable, but lacked a proper analyzer for that. After some thought, Patrick decided that we would just give it a go one at a time. We surfaced and knelt close together as Patrick closed his DSV and took a short breath of the gas. Wearing an expression resembling somebody tasting less-than-appetizing looking food he took a second breath.
Watching intently, I saw the expression quickly change from hesitant but ok, to uncomfortable to concerned as he put his DSV back in and opened it. I was ready for him to pass out as we sat there breathing, but nothing happened. We knew it was likely not breathable, but I wanted to see what it felt like! I removed my DSV and took a breath. A humid, thick, shockingly hot breath filled my lungs and I was not going to take a second one. No way that was safe, I thought, as the burning in my lungs slowly faded.
Patrick climbed out with just his rebreather (and flowing oxygen) and took a quick look around, but no luck. As he was getting dressed again, I popped my head into a few holes and found a passage that looked to slope downwards on the other side of a tight squeeze. I ran a line in with Patrick behind me, and tried to push through but couldn’t fit. After removing myself and the cloud of unavoidable silt surrounded us, I grabbed the rock that was in the way and flipped it over. If you have ever moved a big rock in a collapse, in a never-before-dived cave, you can imagine the visibility afterwards. We backed out, went to check a few other places, then returned hoping for slightly better visibility.

Patrick was the next one in, leaving a tank on the line with me this time, and he extended the line down the slope on the other side. I heard rocks falling, tanks banging on rock, grunting, laughing, bubbles moving along the ceiling, and then he returned with his hands shaking like crazy. Whatever was over there, was not for the faint of heart it seemed. After a bit of cooling down, he went back into the cloud, which was followed by loud yelling. Excited yelling. We exited, and planned our return for the next day. What lay beyond the 6 m/20 ft deep, vertical, awkward, tank-off restriction was an open space that continued downwards to what appeared to be 40 m+.
The next day, I was going through first. We rehearsed the shape of the restriction and the series of movements needed for passing it on the surface. It was weaving through the space where collapsed boulders met the sloping ceiling, and any extra force on the wiggling rocks meant possible collapse. The plan was for me to pass, tie into the EOL, and head off. Patrick would pass behind me with the MNemo and survey in. Adding tie off after tie off, I headed deeper, then flattened out, then up through an opening to my right. Now it was my turn to yell, the cave had returned to its previous enormous size!! This celebration lasted three tie offs, as we climbed yet another collapse that was quite clearly the end. Cut line, put reel away, look around knowing that nobody will ever be here again, and head home.
On to Anjanamba
Several options lay ahead of us, which Patrick and Phil weighed over dinner. Continue searching in Malazamanga, or get the filming done then head north to Anjanamba, or spend the next two weeks surfing. The last option was apparently way more valid than the joking suggestion I had taken it as. Fortunately, the second option was the choice. We spent a day scootering around with lights in hand and on the DPVs. Screen grabs of the video were used as photos for this article.
We also had two surfing days, where I (having never surfed before) mostly tried to not get annihilated by the waves. My second goal was “not to kill anybody” as Patrick and Phillip repetitively warned me not to do it with my oversized board (only a stand up paddle board was available). Fortunately I’m a very strong swimmer, as I spent large chunks of time crashing and burning, then being tossed around by the ocean.
”This is the most epic cave ever”
Phillip Lehmann on Anjanamba
Heading up to Anjanamba featured a boat ride, a seven hour drive that resembled one of those truck commercials trying to show how tough its product is, and a journey through the Mikea National Park which had no paved road either. During lunch break everybody commented how much better it is now than it was several years ago, describing it as “pretty smooth” and “less violent” in the same sentence.
We visited the local village, where residents are the spiritual keepers of Anjanamba, to talk to the chief and say hi to a friend of Tsoa who had just had a baby. While there we got a tour of their newly built school, joked with the children a bit, took a photo and headed home. For a lifestyle that is so drastically different to our own, with so much less of everything tangible, the village seems a happy, lively place with kids running and playing. However it is easy to see the need for food, schooling, health products, and basic medical care to name a few.

Appeasing the Spirits of Anjanamba
Anjanamba is the location of the filming of the “Spirits of the Cave ” series (see DIVE DEEPER below). Described as a much more dendritic, Mexican-like cave with a blue color that puts the famous Mexican salt water tunnels to shame. The name of the series doesn’t come from nowhere; this cave is home to several spirits. In order to appease them, a few things need to be accomplished.
First, we must visit a big, double trunked baobab during the walk there. We remove our hats, gather near the meeting point of the trunks, place a pointer finger on one tree and pinky on the other (think bull horns hand shape), bow our heads and ask the spirits for two things. One, that they allow us to find an epic cave that goes. Two, that they grant us safe passage and everybody returns home safely. The ever-present, always watching lizard that lives there looked down in approval. The locals however, who had no idea what we were doing, waved us back to the path with a smile and laugh.
Once that is done, a ritual must happen with the Mikea people (in which the National Park is named after). Patrick and Phil have already been through it, so it’s just me. The chief started the ritual, as they each took a sip from a bottle of rum we had brought. Tsoa explained to me afterwards what they had been saying (asking the spirits to accept me, safe passage etc). Notably, it included nothing about finding mega cave, but we had already covered that during the lizard tree ceremony I guess.
The guys had warned me about the second part of the ritual, which had me eating a part of the cave – sand, dirt, rock, whatever. The chief continued speaking, and Tsoa told me it was time. I pinched some sand, put it in my mouth and swallowed. Phillip verified it was all gone. In the background I hear Patrick stifle a laugh, and my long-held suspicion was proven true, this was not actually part of it. The locals found it hilarious, and it wasn’t as if I was going to say no in any case. Diving time.
As usual, we were quite late and had made very ambitious plans which didn’t quite pan out. But we did as much as we could, then headed back to our new home at “Laguna Blu.” Like in Anakao, we had great food, friendly staff, beautiful views and comfortable sleeping.

Reel Bashing
Having laid less line than we had hoped in Malazamanga, we were keen to “bash some reels”. Anjanambas current EOL lay at more than 2287 meters/7500 feet with an average depth of 18m/60 ft or so. It featured enormous tunnels and decorated rooms, yet consistently turned into tight, never-quite-ending spaces before returning to vast rooms with pristine formations all over the place.
Patrick and I each carried a stage, and I carried the back up scooter. Passing through the 30 minutes of sideways swimming, weaving up and down, belly scraping, up and down cave with a negatively buoyant scooter in between my legs meant it was not always smooth sailing. Fortunately it usually got stuck when I was in the back so nobody saw. We reached the end of the line, Phillip tied in and headed off with Patrick recording and me surveying behind them.
From my POV, it looked likely to end every 10 tie offs only for the line to weave into a little corner of the room and continue, with nothing but a light dusting of silt at each tie off as signs of my team ahead of me. This repeated for another 457 meters/1500 ft of line until the reel was emptied, everybody cheered and fist bumped with excitement and then decided that we really needed to head home.
Our DPV charging plan didn’t pan out, so after each day Patrick and Phil drove over to a neighboring location and ate lunch while the scooters charged. I went back to Anjanamba and swam some of the closer lines checking for any going cave. After extending a few EOL’s, the sections had been checked without much luck. After a few days of exploring in Anjanamba, which mostly featured a repeating pattern of restrictions then big rooms, we finished our last diving day with nothing clearly going, but a few hopeful areas left.

End of the Line
As we reached the end of the trip, instead of feeling tired as we expected, we found ourselves ready for more. We had lots of sorb left, but had used every last liter of oxygen. Unfortunately, it was time to take a group photo with the locals, dry our equipment and start the journey home. Not only did we have flights to catch, but we had classes to teach less than 12 hours after landing in Mexico.
After five weeks of expedition, we had managed to get the most out of every day, be on time almost never, and explore some amazing cave. More impressively, I don’t recall a single argument or bad mood at all, which is rare when you spend 18 hours per day with the same people. Until next time, the villagers return to their normal lives, we go back to the Caribbean, and the spirits of Anjanamba can rest again.
We did have one last day before heading home, in which we would make a discovery. What will come of it is yet to be seen, but I’m sure it’s going to be a mega-epic either way. In fact, probably the most epic cave ever.
DIVE DEEPER
The Protec Team‘s past Madagascar Expeditions:
YouTube: Spirits of the Cave (2017)
YouTube: Spirits of the Cave 2 (2019)
YouTube: Spirits of the Cave 3 (2020)

Originally from Canada, Jake Bulman is a full-time cave diving and CCR instructor at Protec Dive Centers in Mexico. The last several years of teaching have been almost exclusively sidewinder focused, from try dives to CCR Cave classes, 4C to 24C, and in several countries around the world. Outside of work, he can be found on exploration projects in local caves of a wide range of depths, distances, and sizes.