Harry's Wacky World

Caving in the Cenotes of the Riviera Maya
Quintana Roo, Mexico
February 2009

All photos are copyrighted by the given author
All photos were reduced in quality for internet publishing

INTRODUCTION

On February 1, 2009, just days before a big snowstorm, I boarded a plane bound for Mexico for 10 days of caving. We landed in sunny Cancun on the northeastern tip of the Yucatan Peninsula ("The Riviera Maya"), and drove down to "cave country" near Tulum.

The Riviera Maya extends from Cancun to Tulum along the northeastern tip of the Yucatan Peninsula.

Near Tulum, in Puerto Aventuras, I met up with Leo (United Kingdom), Tom (United Kingdom) and our cave diving instructor Steve Gerrard (an American expat). During our stay in Mexico we completed the following four courses from the Professional Scuba Association International (PSAI) and the National Association for Cave Diving (NACD):
Cavern Diver
Intro to Cave
Apprentice Cave Diver
Full Cave Diver

Leo and Tom were technical wreck divers from the U.K. who were going caving for the first time. Of course, I was a caver who got into scuba diving. It didn't seem to matter from which direction you approached cave diving.

Leo (left), Tom (center) and Harry (right) on the surface at Cenote Dos Ojos.
(Photo by Steve Gerrard)

Harry (left), Tom (center) and Leo (right) in a cave.
(Photo by Steve Gerrard)

PRELUDE

This story actually began five years ago, in May 2004. That is when my girlfriend Jackey and I became certified open-water scuba divers in the Bahamas. My motivation from the very beginning was cave diving. As I gained more diving experience I quickly realized that I had vastly under-appreciated the skill, proficiency and dedication that would be required to be a cave diver. Living in West Virginia I was getting only about 30 dives per year, far short of the 100+ dives per year that was recommended to become a proficient technical diver. My few failed forays into "pre-tech" scuba courses just proved that I wasn't getting enough experience.

Other than giving up on my dream of cave diving, or moving to Florida, the only other viable solution didn't seem that viable. I had to get a compressor so that I could dive whenever I wanted to dive in the local reservoirs. The thought of establishing my own fill station was so depressing that I did nothing but obsess over the problem for at least a year.

I knew that initially I would have to get trained and certified in scuba gas mixing, fill station operation and cylinder inspection. Then I would have to purchase an expensive compressor with all of the accessories and high-pressure storage tanks. That would also require a variety of gas analyzers and specialized monitoring equipment. I would need to hire an independent laboratory to verify that my scuba gas mixes were breathable. Throw in dozens of specialty tools, calibration equipment and ultra-violet inspection scopes, and you're looking at a massive investment in cash and time. As if those thoughts weren't bad enough, I started having nightmares of high-pressure tank explosions and raging fires in my garage fueled by high-pressure oxygen. "How bad to you want to be a cave diver, Harry?"

By February 2008 I had a fully-operational high-pressure fill station in my garage. Getting to that point was a long and tedious process. First, all parts (valves, connectors, etc.) were completely disassembled to their machined components and then meticulously degreased in an ultrasonic cleaner. The parts were then retro-fitted for oxygen service using oxygen-compatible lubricants (Cristo-Lube) and Viton o-rings. All components were then reassembled and tested.

An independent analytical lab verified that my gas was significantly cleaner than Grade E Oxygen-Compatible Air (OCA) standards. My custom gas blender allowed me to prepare any scuba breathing mix on the fly, from plain air all the way to EAN 40. A few modifications and I'll be preparing Trimix as well. I analyze all of my blends for oxygen content and carbon monoxide contamination, using sensors that I regularly calibrate with commercial calibration gasses. (The complete story of my home compressor project can be found here.)

My fill station, showing the electric Alkin W31 compressor, Nitrox blending stick, manifold, oxygen (green cylinder) and storage tanks (blue cylinders). There is one yoke fill whip and one DIN fill whip (in use). (Photo by Harry Marinakis)

After my compressor came on line, I knocked out about 100 dives in just seven months. Most of my dives were solo forays into the cold, dark waters of Tygart Reservoir and Summersville Lake. Underwater, I performed drills for hours at a time, trying to perfect my buoyancy, trim, propulsion and other skills that must be over-learned by a tech diver. When the boredom of the drills was unbearable, I'd push the limits of my nerve by descending alone into the inky depths of the lakes. I would follow the muddy bottoms at depths of over 100 feet, where the light from my torch penetrated only 3 or 4 feet into the murky water.

In November 2008, I contacted Steve Gerrard to sign up for his cave diving course.

"I think I'm ready now," I wrote to Steve with as much confidence and courage as I could muster.

Steve Gerrard, cave diving instructor extraordinaire. (Photo by Harry Marinakis)

THE CAVE DIVING COURSE

The night before our class began, I told Steve Gerrard of my plans for the class. I would start the Cavern Diver course and, according the Peter Principle, I would rise to my highest level of incompetency. When that occurred I would leave the class to remediate with another instructor so that Leo and Tom could continue the cave diving course unimpeded. Well, that was the plan.

The next morning we all met in the grassy courtyard of the condominiums to review equipment configuration, practice guideline and reel work, zero-visibility touch-contact communication and other cave diving procedures.

Simulated zero-visibility touch-contact drills in the courtyard. (Photo by Steve Gerrard)

That afternoon we drove over to Cenote Dos Ojos for our introductory cavern dive. After the dive, while we were still floating in the cool water of the cenote in the shade of the cave entrance, Steve announced a change in plans. He informed us that because of our proficiency we were going to start diving more difficult caves that were more commensurate with our skills. We would see caves that don't usually see cave diving students.

All of that hard work finally paid off!

Steve Gerrard is a good-natured and world-famous cave diving instructor in the Riviera Maya. His style is easy and reassuring. Some instructors take students to only a few caves to drill, drill, drill. Steve, on the other hand, takes students to many different caves and dives, dives, dives. Students gain first-hand experience with real problems (such as primary light failures) just because they dive so much. We did many drills anyway, but at least the entire cave trip was not centered around drills.

All in all, we did 19 caves dives, logged over 1,100 minutes of bottom time, and dived in 9 different caves. A "short" dive was 75 minutes and "long" dive was over 2 hours! There were days where we swam over 10,000 feet in the caves in a single day. I have never been more exhausted and laughed so much in my entire life.

THE CAVES

Sixty-five million years ago the area that is now the Yucatan Peninsula was a vast oceanic reef. Plate tectonics pushed the reef above sea level. During the most recent glaciation, solutional caves formed in the exposed limestone. These caves are as highly decorated as Carlsbad Caverns. The recession of the glaciers during the current interglacial period caused the sea level to rise and flooded the caves.

The caves of the Riviera Maya (shown here) are as highly decorated as Carlsbad Caverns. (Photo of Tom by Steve Gerrard)

Cenotes are sink holes flooded with water. The modern term "cenote" is derived from the ancient Mayan word "D'zonot." Many of the cenotes in the area still bear wonderful Mayan names, such as Nahoch Nah Chich, Xunaan Ha, X'Kekan, Ox Bel Ha, Sak Aktun, Ixkil Kuzan, and many others.

Many of the caves in the Riviera Maya contain a halocline, an interface between lighter inland fresh water and denser salt water from the ocean. The fresh water actually floats on top of the salt water. The interface is so very well demarcated, in fact, that looking down on the halocline from above gives the illusion that you are looking onto the surface of a lake. There is a similar illusion when looking upwards at the halocline. Due to the different refractive indexes of fresh and salt water, visibility is greatly reduced when you swim through and disturb the halocline. When following another caver through a halocline, all you can do is maintain contact with the guideline and follow the blurred light ahead of you.

This is what a halocline looks like from below.
Photo by Steve Gerrard

A simulated view of what disturbing the halocline does to the visibility. Left: normal. Right: disturbed halocline. The distortion is so bad that you cannot even read your gauges.

The caves of the Riviera Maya are also very shallow. You can traverse thousands of feet of cave passageway never get deeper than 40 feet. This enables cave divers to get extremely long bottom times (e.g., 2+ hours) without incurring a decompression obligation. Of course, there are really deep caves if you want to go deep.

EQUIPMENT CONFIGURATION

Harry at Cenote Chac Mool with a standard Hogarthian-style cave diving configuration.

We used a standard Hogarthian-style cave diving configuration:

1. Continuous-weave harness with 5 D-rings
2. Stainless-steel back plate
3. Twin, banded cylinders with an isolation manifold
4. Two independent 1st stage regulators
5. One second-stage regulator on a 7-foot hose
6. One second-stage regulator on a necklace bungee
7. Primary light (HID or LED) with a burn time of at least 4 hours
8. Two back-up lights (LED)
9. Dry suit
10. Hood
11. Mask and back-up mask
12. Wet notes
13, Cutting devices
14. Primary reel
15. Safety reel and spool
16. Line arrows
17. Fins with spring heels
18. Deco tables
19. Depth gauge
20. Bottom timer

Tom at Cenote Car Wash showing the Hogarthian configuration. (Photo by Harry Marinakis)

In the heat and humidity of the jungle, it was not pleasant crawling into heavy winter long johns and a dry suit. But when you spent hours in the cool water of the cenotes (75 degrees F) it was the best way to stay warm. (Photo by Steve Gerrard)

Tom and Leo at Cenote Chac Mool, showing the twin, banded 3ALM-S80 cylinders with isolation manifolds. The cylinders alone weigh 87 pounds. Add in the back plate, regulators, light, etc., and the total weight on your back is approximately 115 pounds.
(Photo by Steve Gerrard)

This little sign marked the "gas station." (Photo by Harry Marinakis)

The "gas station" where we got all of our Nitrox fills. (Photo by Harry Marinakis)

PSYCHOLOGICAL ASPECTS

I had no illusions about cave diving. Just because I was a caver didn't mean that I would automatically feel at ease squirming into a tiny worm hole 3,500 feet back in a flooded cave with scuba cylinders on my back. I really didn't know what to expect of myself.

There was a drill that I secretly dreaded. We would simulate an out-of-air emergency in simulated zero-visibility in restricted passageway. In practice, this drill involved donating a regulator to the simulated "out-of-air" buddy, turning off your lights, and then feeling your way out of the cave single-file in total darkness. You had to negotiate the rocky restrictions, all the while maintaining air-sharing and touch contact with your buddy.

I'll admit, too, that I was a little nervous during our first really deep cave penetration. However, after that dive, nothing seemed to register on my Anxiety-o-Meter. I felt quite at home in the cave. So did Leo and Tom. In fact, it became quite exciting to push deep into cave, or squeeze through little worm holes. I was pleasantly surprised.

SELECTED CAVE DIVES

CENOTE DOS OJOS (Spring Side)
Systema Dos Ojos
Max Depth: 27 feet
Dive Duration: 50 minutes
Water Temp: 75 degrees F
Back gas: Air

Cenote Dos Ojos.
(Photo by Steve Gerrard)

This was our very first cavern/cave dive. We penetrated into the spring side of the cenote and followed the main line until we turned at 1/6. (Start 3,000 psi; Turn 2,500 psi; Exit 2,000 psi)

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CENOTE DOS OJOS (Siphon Side)
Systema Dos Ojos
Max Depth: 29 feet
Dive Duration: 42 minutes
Water Temp: 75 degrees F
Back gas: Air

Cenote Dos Ojos.
(Photo by Steve Gerrard)

We penetrated into the siphon side of the cenote and followed the main line. The current carried us into the cave but we had to kick hard against the current to exit the cave. I don't like diving into siphons. (Start 1,900 psi; Turn 1,600 psi; Exit 1,300 psi)

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CENOTE CHAC MOOL (Spring Side)
Systema Chac Mool
Max Depth: 46 feet
Dive Duration: 53 minutes
Water Temp: 77 degrees F
Back gas: EAN32

Cenote Chac Mool.
(Photo by Steve Gerrard)

We penetrated into the spring side of the cenote and followed the main line into the GIANT passageways of Chac Mool. There was a very pronounced halocline and the salt water was too warm for my taste. (Start 3,050 psi; Turn 2,300 psi; Exit 1,500 psi)

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CENOTE CHAC MOOL (Siphon Side)
Systema Chac Mool
Max Depth: 41 feet
Dive Duration: 33 minutes
Water Temp: 77 degrees F
Back gas: EAN32

Harry walking down to Cenote Chac Mool.
(Photo by Steve Gerrard)

We penetrated into the siphon side of the cenote and followed the main line. The passageway was smaller and nicely decorated. (Start 1,500 psi; Turn 1,200 psi; Exit 900 psi)

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CENOTE DOS PALMAS (Spring Side)
Systema Dos Ojos
Max Depth: 34 feet
Dive Duration: 1 hour, 18 minutes
Water Temp: 75 degrees F
Back gas: EAN32

Cenote Dos Palmas. (Photo by Harry Marinakis)

We penetrated into the spring side of the cenote and followed the main line. This was our first deep cave penetration, about 2,500 feet. (Start 3,000 psi; Turn 2,000 psi; Exit 1,300 psi)

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CENOTE CARACOL
Systema Caracol
Max Depth: 29 feet
Dive Duration: 1 hour, 54 minutes
Water Temp: 75 degrees F
Back gas: EAN32

Tom (left), Leo and Harry at Cenote Caracol.
(Photo by Steve Gerrard)

The hole of Cenote Caracol. It was not pleasant climbing up these steep stairs with all the gear. It is said that the most dangerous part of cave diving in the Riviera Maya is getting into and out of the cenote. (Photo by Steve Gerrard)

Cenote Caracol was small but spectacularly-decorated cave. If it had been dry, the caving would have been stoop-walking and crawling. We penetrated deep, about 3,500 feet, gliding carefully through dense stalactites, stalagmites and columns. (Start 3,000 psi; Turn 2,000 psi; Exit 1,000 psi)

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CENOTE CARACOL
Systema Caracol
Max Depth: 24 feet
Dive Duration: 1 hour, 19 minutes
Water Temp: 75 degrees F
Back gas: EAN32

Tom humping more 87-pound cylinders back through the jungle to Cenote Caracol. (Photo by Harry Marinakis)

Leo setting up gear at Cenote Caracol. (Photo by Harry Marinakis)

This dive introduced us to more complex cave navigation. We jumped from the main line to a side passageway. Total penetration was about 1,800. For practice, we exited on our back-up lights. (Start 3,000 psi; Turn 2,000 psi; Exit 1,000 psi)

All-you-eat BBQ in the jungle at Cenote Caracol. (Photo by Steve Gerrard)

The BBQ. (Photo by Harry Marinakis)

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CENOTE CAR WASH (Cenote Aktun Ha)
Systema Car Wash
Max Depth: 61 feet
Dive Duration: 1 hour, 33 minutes
Water Temp: 77 degrees F
Back gas: EAN32

The sign at Cenote Car Wash. (Photo by Harry Marinakis)

Cenote Car Wash. (Photo by Harry Marinakis)

Cenote Car Wash was named for a former local practice, but fortunately that has stopped since the owners have taken a more ecologically-friendly position. Deep in the cave lies a large, spectacular room that is heavily decorated with tall stalagmites and totems. A cave diver once said that the room was so beautiful that it brought tears to his eyes, so the room was named "The Room of Tears." Years ago it was on the "Must Do" list for all cave divers. The cave it not as fragile as some of the other caves, which is fortunate because there are a lot of tight holes that you must negotiate to get back to The Room of Tears. (Start 3,000 psi; Turn 2,000 psi; Exit 1,000 psi)

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CENOTE CALAVERA (Temple of Doom)
Systema Temple of Doom
Max Depth: 58 feet
Dive Duration: 29 minutes
Water Temp: 79 degrees F
Back gas: EAN32

The ladder at the Temple of Doom. Entry was easy. It was a 10-foot giant stride into the water! But climbing up this vertical older ladder with over 115 pounds on your back was no easy task. (Yes, the ladder is hanging from that old dead tree!) (Photo by Harry Marinakis)

Cenote Calavera is a complex cave where we continued to hone our reel, guideline and navigation skills. We performed numerous jumps and circuits. Our first dive in Cenote Calavera was a short circuit. (Start 2,950 psi; Turn 2,500 psi; Exit 2,200 psi)

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CENOTE CALAVERA (Temple of Doom)
Systema Temple of Doom
Max Depth: 60 feet
Dive Duration: 1 hour, 9 minutes
Water Temp: 79 degrees F
Back gas: EAN32

Our second dive into the Temple of Doom led us through multiple intersections, through the "Hall of Giants," and finally a jump into the famed "Madonna Passage." We got to see both the Madonna Formation and "The Fang." (Start 2,200 psi; Turn 1,500 psi; Exit 900 psi)

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CENOTE XUNAAN-HA (Siphon side)
Systema Xunaan Ha
Max Depth: 41 feet
Dive Duration: 28 minutes
Water Temp: 77 degrees F
Back gas: EAN32

The sign at Cenote Xunaan Ha. (Photo by Harry Marinakis)

Hiking back to the cenote. (Photo by Steve Gerrard)

Cenote Xunaan Ha. (Photo by Harry Marinakis)

We did a short siphon-side penetration into Xunaan-Ha.

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CENOTE XUNAAN-HA (Spring side)
Systema Xunaan Ha
Max Depth: 31 feet
Dive Duration: 1 hour, 27 minutes
Water Temp: 77 degrees F
Back gas: EAN32

Tom getting ready for a deep penetration into Cenote Xunaan-Ha. (Photo by Harry Marinakis)

Our second dive at Cenote Xunaan-Ha was a deep penetration into the spring side. (Start 3,000 psi; Turn 2,000 psi; Exit 1,000 psi)

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CENOTE PET CEMETARY (The Blue Abyss)
Systema Nahoch Nah Chich
Max Depth: 100 feet
Dive Duration: 2 hours, 7 minutes
Water Temp: 75 degrees F
Back gas: EAN32
Stage cylinder: air

Our dive into The Blue Abyss of Cenote Pet Cemetery was our most advanced and complicated dive. We used stage bottles to extend our range and made several jumps to secondary and tertiary passageways.

The Blue Abyss is a giant room in the Nahoch Nah Chich system. It is approximately 100 feet or more in diameter and drops to breakdown boulders at 240 feet. The upper 80 feet are highly decorated with monumental columns, massive flowstone and sheets of 40-foot high stalactites. Although The Blue Abyss is nearest to Cenote Pet Cemetery, it is still a long way from any cave entrance.

We departed Cenote Pet Cemetery on the main cave line breathing from 80-cubic foot stage cylinders slung on our left D-rings. We made two jumps to secondary passageways and struggled through the "King Pong Restriction." This was a tight little hole between aggregations of columns, made all the more tight by the three cylinders that encumbered us. Further down the line we cached our stage cylinders and continued on back gas alone (EAN32). We made one more jump to a small tertiary passage and then... the bottom dropped out from beneath us. We emerged from a small, winding passageway with dense decorations into a huge black abyss.

The neon-blue glow of my digital depth gauge reflected in the glass of my mask as watched the numbers tick away. 80 feet... 85... 90... 95... I inhaled deeply to arrest my descent at 100 feet. I hovered there in the middle of this black hole and shined my light straight down. It was obvious that I was less than half way to the bottom. But I had previously decided that I would go no deeper than 100 feet on this dive, and I was sticking to my dive plan.

Next I covered my dive light with my hand to savor the utter blackness. The lights from my buddies flickered around me like fireflies. Occasionally I shined my light on a distant wall just to reassure myself that I was truly alive and someplace real, not just some severed consciousness adrift in the vacuum of space.

Yes, I was somewhere. I was thousands of feet back in a deep cave, floating in a surreal black hole at 100 feet. There was complete silence, save for the noise of the life-support pack on my back. It clicked and hissed when I inhaled and bubbled when I exhaled. Neil Armstrong, you ain't got nothing on me anymore.

Frequent checks of the faintly-glowing pressure gauge brought us back to reality. It was time to head out of the cave. We spiraled up the massive room, admiring the giant columns up close. We followed our guideline back, pulled our jump reels, collected our stage bottles, and returned to the sunny surface after a flawlessly-executed cave dive.

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CENOTE PET CEMETARY (Dark Side of the Moon)
Systema Nahoch Nah Chich
Max Depth: 36 feet
Dive Duration: 1 hour, 28 minutes
Water Temp: 75 degrees F
Back gas: EAN32

After our long dive into The Blue Abyss, we did a "short" dive (88 minutes) into the "Dark Side of the Moon" passage.

An open-air cabana on the beach where we had lunch after diving at Cenote Pet Cemetery. (Photo by Harry Marinakis)

The "emergency exit!" (Photo by Harry Marinakis)

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GRAN CENOTE
Systema Sak Aktun
Max Depth: 40 feet
Dive Duration: 32 minutes
Water Temp: 77 degrees F
Back gas: EAN32

Gran Cenote was truly a grand place. (Photo by Harry Marinakis)

Gran Cenote. (Photo by Harry Marinakis)

Our graduation dive was a photo shoot in the Cuzan-Ha loop. Many of the photos included here by Steve Gerrard are from this dive.

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GRAN CENOTE
Systema Sak Aktun
Max Depth: 42 feet
Dive Duration: 1 hour, 16 minutes
Water Temp: 77 degrees F
Back gas: Air

Starting the dive in Gran Cenote. (Photo by Harry Marinakis)

My first cave dive without a guide was the Paseo de Legarto passageway in Gran Cenote. We ran the main line and then jumped into Paseo de Legarto.

CAVE DIVING PHOTOS