Is Cenote diving for Me?

You are planning a dive trip to the Yucatan Penninsula in Mexico? Then you might have come accross some amazing pictures of the beautiful Cenotes. Once stunned by these pictures you probably want to see it with your own eyes and live the experience.

But this question keeps popping up: is Cenote diving for me?

  • What are Cenotes?

Deep Cave diving in the Cenotes of Yucatan, Mexico
Deep Cave diving in the Cenotes of Yucatan, Mexico

Cenotes are sinkholes distributed all over the Yucatan Peninsula. They are the window to the underwater caves and caverns. And they are one of the main dive attraction in the area and one of the top dive destination in the world.

Those caves are highly decorated with stunning formations such as stalagmites and stalactites which makes them very unique.

Your first Cenote diving experience will probably be a cavern tour. You are not required to have a cave diving certification as you will not be technically entering the cave.

  • What is a cavern dive?

A cavern dive is the exploration of a natural overhead environment while remaining within sight of natural light.

When diving in the Cenotes you will always see natural light and have a sight of a direct way out of the cavern. However do not underestimate safety by thinking it is an easy dive. And here are some thoughts to consider before going for a cavern dive.

  • Will I be swimming in tight places?
Gran Cenote - Cavern diving in Tulum
Gran Cenote – Cavern diving

No you won’t!

It is a requirement for all cavern dive in the Cenotes to go through areas where two divers can fit side by side at all time. You will not swim in any tight areas.

Should any problem arrize you will be able to swim side by side with your guide to exit the cavern.

  • Can accidents happen while Cenote diving?

Yes, it can happen…

Your cavern guide should be a qualified divemaster or instructor in teaching status and a certified cave diver. Of course the more experienced the better the guide can react to a bad situation. And the more he/she knows the site, the better he/she can handle the situation.

Cavern diving by the book, is really safe. The conditions are optimal: shallow dives, no current, great visibility, group size limited to 4 divers maximum per guide and all divers should be experienced.

We recommend you to choose carefully your dive operator or guide. And remember the most experienced the guide the better he/she can show you around and yet commit to safety and conservation.

  • Is it dark down there?

Yes it is!

Safety Rules for Cavern diving in the Cenotes
Basic safety rules

Some parts in the Cenotes are very dark and darkness can alter your sense of orientation, and you a feeling you could get lost easily. This is why everyone is diving with a dive light.

Your guide should be carrying all his/her full cave gear that includes a bright and long lasting primary light used for showing you around and for communication as well as 2 back up lights. And yourself should carry at least one dive light.

The waters in the Cenotes are crystal clear, and will stay that way if all divers follow the basic rules: maintain good buoyancy, swim using non silting kicking techniques and follow the guideline.

  • Will I be able to find my way?

Yes, as long as you follow the Guide Lines

Full Cave Diver course - deploy a guideline
Installing a guideline

One of the main safety rule in cavern diving in the Cenotes is referencing the guideline at all time. Your guide will explain how to identify it, how to use it and where to position yourself at all time. The same guideline will show you the way out. You should also be able to rely on your guide to follow them at all time.

We strongly recommend to dive the Cenotes. It is a unique and magical experience. Always make sure you dive well within your limits and remember the golden rule: anyone can call the dive, at any time, for any reason. So, do not hesitate to do so whenever you don’t feel comfortable.

When comes the time for you to book your dive tour to the Cenotes, remember that safety is important. Cenote diving is for advanced divers and you should be sharp on your dive skills, so don’t hesitate to refresh them by a couple ocean dives before you head for the cenotes.

Enjoy your Cenote dive 🙂

Contact us for some private guiding or personalized group packages: CONTACT

Cenote Kukulkan, cavern dive in the winter morning light
Cenote Kukulkan, cavern dive in the winter morning light

Cenote Taj Ma Ha: an amazing Cavern Dive


The amazing cenote Taj Ma Ha is one of the best Cenote for cavern diving tours in the Riviera Maya. Don’t miss this unique diving experience.


Cenote Taj Ma Ha is located about 5 km south of Puerto Aventuras. You drive on a bumpy dirt road in the jungle to the parking area. There you will find bathroom facilities and tables to prepare your gears. From there a short walk down the stairs will lead you to the water.

The Cavern dive

The cavern dive is one of the most amazing and most diverse dive in Cenotes. During the circuit you will dive past several cenotes: Cenote points of light, Cenote Sugar bowl and Cenotes Esmeralda. Each of them offering outstanding light effects.

Cenote Taj Ma HaFrom March to September, you will enjoy one of the most spectacular light shows. The sun is high up in the sky and enters through small apertures in the ceiling of the Points of Light Room. Laser like beams of light will give you the opportunity to enjoy one of the most spectacular light show nature can offer.

In the deeper areas you will cross halocline tunnels. The halocline creates a surprising mirror light effect as you enter the salt water layer, below the fresh water.

These tunnels will lead you to some beautifully decorated areas with a lots of speleothems like stalactites, stalagmites flowstones.

You will surface in cenote Sugar bowl where, you’ll be able to have a unique view over the jungle and maybe spot a Motmot, a sacred bird with stunning colours, often observed in the proximity of the Cenotes. Its very distinctive voice will loudly announce its presence.

Throughout the dive, you will observe lots of fossils in the walls and the ceiling of the cavern. 


This dive has a saw tooth profile and will require extremely good buoyancy control at all time. You will then make sure you don’t damage any part of the cavern and fully enjoy the adventure.

To get the best of your experience we also recommend to book a private tour with an experienced guide.

Maximum Depth: 45 feet (14 meters)


Video from two divers on a private tour at Cenote Taj Ma Ha

Contact us for a private guiding service in the cavern of the Cenote Taj Ma Ha

Group rates available starting from 4 divers


Cave diving – Line protocols

Line protocols in cave diving


line protocols
Full cave diving course – Use of directional and non directional markers

Guidelines are the life lines used by cave divers to reference the exit in underwater caves. In case of loss of visibility the guideline will lead to the way out of the cave, back to the surface and to ambient air. One of the main reason for fatalities in cave diving involves the lack of use of a continuous guideline. It can be either for not running a temporary line from the open water to the permanent guideline or for passing from one line to another.

For maximum safety, cave divers follow a continous guideline  that can lead them all the way to the surface, even in total darkness. Directional markers such as arrows and personal non-directional markers such as “cookies” or REMs on the lines clearly indicate the exit.

Permanent Lines

Permanent lines are installed permanently in the cave to insure a properly installed guideline for further going exploration and visiting cave divers.

The permanent lines are often referred to as main line. They can begin close to the cave exit or further into the cave hidden from open water divers and prevent them to go into the cave without proper training. Divers travel to the mainline with a primary reel in order to keep a continuous guideline from the open water.

Navigation in Caves

In most caves, especially in the Yucatan peninsula in Mexico, there are more than one permanent line therefore the divers have to navigate inside the cave. There are permanent intersections, referred to as a “T“.

Sometimes a diver has to phisically move from one line to another this is a jump. It can go from the end of one line to the middle of another, or from the middle of a line to the end or middle of another.

A gap is when going from the end of one line to the end of another.

Personal line markers properly mark the exit. It has to be in a clear way in order to be understood in zero visibility. The diver will be able to find the way to the open water area of the cave entrance.

Gap and/or Jump Lines

Divers have to install a temporary gap or jump line to go from one line to the other. Line markers such as directional or non-directional should also indicate and mark the exit.

Laying line

Proper use of reels and placement of lines is essential for efficient cave diving. The line has to be laid maintaining tension. It should be placed close to the cave floor so divers can swim above it.
A primary tie off should be made in open water where direct ascent to the surface is possible. It is followed by a secondary tie off in the cavern zone. Should the primary tie off come loose the second one will keep the line in place. Further on a tie-off or placement must be made whenever changing direction in order to avoid line traps.

Line Markers

Line markers indicate directions or mark survey or science stations. They can be directional (arrows) or non-directional markers (cookies, clothespins, REM). Personnal non-directional markers are mark locations or exits and will not cause confusion for other teams.

You will learn more about the use of guidelines and line markers and practice their uses in real caves and various scenarios during your cave diving training.


About the Cenotes


The word “Cenote”, comes from the mayan “D’zonot” and means “well”.

Cenotes are natural pits, or sinkholes, resulting from the collapse of limestone bedrock therefore exposing the ground water underneath. Cenotes are common geological forms in low latitude regions, particularly on islands, coastlines, and platforms with young limestones with little soil development. They spread all over the Yucatán Peninsula of Mexico. The term “cenote” also describes similar karst features in other countries such as Cuba and Australia, in addition to the word “sinkholes”.

Diving into the cenotes is like diving into the history of the peninsula of Yucatan and much more. It gives a wonderful chance to appreciate the evidence of geological changes, archeological discoveries, extinguished species fossils…

The best way to discover the Cenotes will be by cavern diving or cave diving, getting cave diving training.



Cenotes are the connections to the subterranean water bodies. They can feature large open water pools or small sheltered pools. Sometimes they do not have any exposed water. There are over 6000 different cenotes in the Yucatan Peninsula in Mexico.

Cenote waters are usually crystal clear, as the water comes from rain water filtering slowly through the limestone. Therefore contains very few particules. For cave divers great pleasure, cenotes sometimes reveal an underlying cave system.

The Yucatan Peninsula is now officially host of the longest cave system in the world, s system Sac Actun with 347 km. Thanks to  many years of hard work and many hours of exploration, active explorers recently connected  Sac actun (264 km) and Dos Ojos (83km) underwater (January 2018).

Cenotes around the world attract cavern and cave divers.

The Yucatán peninsula

CenotesFormed during the Cenozonic era, – 65,000,000 years ago, the peninsula of Yucatan is very young. The entire peninsula was once a reef, but as the water level dropped, the flatland of Yucatan emmerged.

The peninsula is the exposed portion of the larger Yucatán Platform composed mostly of limestone . The whole of the Yucatán Peninsula is an unconfined flat lying karst landscape.

65 million years ago a meteorite impacted in the greater Caribbean Basin. The center of Chicxulub crater is deeply buried  off the north coast of the peninsula near the town of Chicxulub. The famous “Ring of Cenotes”  outlines one of the shock-waves from this impact, which lies more than 1 km below the modern ground surface.

Although cenotes spread widely throughout much of the Yucatán Peninsula, a higher-density circular alignment of cenotes overlies the ridge of the Chicxulub Crater. This crater structure, identified from the alignment of cenotes, along with geophysical methods.


Cenotes - Karst of MexicoLimestone is a sedimentary rock composed primarily of calcium carbonate (CaCO3) in the form of the mineral calcite. It mostly forms in clear, warm, shallow marine waters. It is an organic sedimentary rock that forms from the accumulation of shell, coral, algal and fecal debris. It can also be a chemical sedimentary rock formed by the precipitation of calcium carbonate from lake or ocean water.

Dissolution of the limestone, formation of the caves

For the Chemists this is how it goes:

Cenotes Limestone dissolution – Chemical reactions leading to cave formation

Gunn J. (Ed.) 2003. Encyclopedia of Caves and Karst Science. Routledge. New York

Calcium precipitation in the Cenotes forms a white layer at the surface

Flora and fauna

Flora and fauna are generally more limitted than in the open ocean, however marine animals do prosper in caves. In caverns, one can spot mollis, guppies, cat-fish, small eels and turttles. In the darkest cenotes, the fauna has evolved special features to live in an the absence natural light. For example, most cave fauna doesn’t have pigmentation and is often blind. They are equipped with sensors in order to find food and make their way around in the dark.

Remipede (Speleonectes tulumensis)

Remipedes are primitive centipede-like crustacean. They can grow up to an inch (2.5 cm) and they use venomous fangs to capture their prey. No other crustacean has this characteristic.

Isopod (Metacirolana mayana)

These cave scavengers feed on whatever comes accross their claws (usually smaller crustaceans).

Mexican Blind Fish (Typhliasina pearsei)

A fish species that inhabits the brackish and freshwater layers of the Yucatan’s caves. The albino, sightless fish grows a couple inches (5 cm). And unlike most other fish, it gives birth to live young.


Side mount cave diving in cenote Minotauro

A day off, cave diving

A cave dive at Cenote Minotauro.

Cenote Minotauro is an easy place to reach. You arrive on a parking lot with tables (at the right height)! And new bathrooms 🙂

The access to cenote Minotauro is through a nice stairway and you can just walk into the water.

I have dove a lot in this system in Backmount configuration, however, it is really nice for side mounting and gives access to many more passages. In Side Mount configuration it is much more enjoyable and probably more precise and easier to avoid damage on the cave.  This system goes up and down, reaches the halocline but remains fairly shallow and is a great place for long dives.

The system itself and the dive circuits can seem a bit confusing as you start knowing the system but it is all really pretty. There is a great map of Minotauro by Alessandro Reato, that really gives all its sense to following Ariadne’s line as this place is really a labyrinth.

You will see here a few images of a fun dive with a friend, local instructor. This video has no teaching purpose whatsoever. No pretension, just two local instructors and experienced cave divers enjoying their time cave diving, filming, editing and sharing their passion.

When this dive was finished, as the current had pushed us quite fast towards the exit we still had plenty of air to recalculate thirds and have a short dive on the other side, downstream so beautiful again. But guess what, the camera’s battery was dead!! I guess we’ll have to go again.

See you,



Anchialine caves and their fauna

Great ressources for all passionate cave divers who can never learn enough about cave geology and cave fauna:

You can learn about the caves in Yucatan, the caves in the bahamas and the caves in Bermuda, their geology and their fauna.

Although not up to date it is still great information.

Watch our videos to observe some of the amazing fauna that you may encounter while cave diving in the Yucatan peninsula in Mexico.

Let us guide you into those amazing dives and observe blind fish, remipedes and many more in their natural habitat. (More info about cave diving)




Pozo Azul Exploration Project

Pozo Azul exploration: A fascinating cave exploration project!

Pozo Azul is currently the longest cave dive penetration in the world,
And more than 9.4km of diving accumulated over 5 sumps are required to reach the furthest point from the single entrance.

Located in the village of Covanera, Burgos, Spain, El Pozo Azul is probably one of the most challenging cave exploration project. Already 5 sumps (maximum depth 71m) had been explored. And in 2015 J. Mallinson pushed the exploration solo and discovered a 6th sump and spent a total of 60 hours inside the cave.

In 2001, Jason Mallinson first visited the site with Rupert Skorupka. At that time the known part of the cave was a 1st 700 m sump, then a dry tunnel of 300 metres, followed by a second sump penetrated for 780 m. On that same trip the sump was pushed to 1250 m.

Jason then returned year after year, sometimes with other top divers, and sometimes on his own.

In 2009 the sump was passed after 5160 m – the longest sump to be passed in the world, to reach Sump 3. This was passed in 2011 and proved to be over 3 km long. From this point, the sumps became shorter and the amount of dry passage longer.

Sumps 2 and 3 are actively linked and are in fact one long sump of more than 8km in length.

in 2015 Jason returned solo. He traversed more than 10 km of sump to explore dry passage and find a sixth sump.
Pozo Azul - Survey map
Pozo Azul – Survey map
[Source: Museo de la Prehistoria Dos Ojos]

The Pleistocene Starts about 2.6 to 1.8 million years ago (depending on the source consulted) most recent period of glaciation .
In the earth’s history there have been many stages of cooling, during which there are glacial periods  (cold) and interglacial (warmer).
Ice Age refers to the most recent glacial period which began 110.000 years ago, whose greatest influence occurred around 20,000 years ago and ended about 8,000 a.p. This age or era was characterized mainly by the decrease of the temperature, which resulted in the expansion of glaciers, decreased sea levels (about 120 meters) and the freezing of large lakes. As a result, there were substantial changes in terrestrial and marine environments that forced the movement of species runners which had not been available previously.

Picture from: //
Picture from:

The Ice Age witnessed two powerful events on the planet: the extinction of the “megafauna”, large mammals that had lived without major concerns for millions of years, and the expansion of a new species from the heart Africa to all continents: Homo sapiens. It is estimated that we left Africa 60.000 years ago, we came to Australia 10.000 years later, then to Europe 35,000 years ago and America 15.000 years ago. Some authors argue that the extinction of large mammals was due to human impact.
The wave of extinctions spread sequentially to Australia, Japan, North America, South America and then in some islands such as Cyprus, the Antilles, New Caledonia, Madagascar and New Zealand.