Cenote Diving

Dos Ojos Cenote – A Must Dive Cenote in Tulum

What is Cenote Dos Ojos?

Cenote Dos Ojos (Spanish for “Two Eyes”) is one of the most famous cenotes in the Yucatán Peninsula. It consists of two cenotes connected by an extensive cave system, offering some of the best cavern diving experiences in Mexico.

Originally known as Sistema Dalsocros, Dos Ojos is now part of the Sistema Sac Actun, which, at over 378 km (235 miles), is one of the longest underwater cave systems in the world.

Where is Cenote Dos Ojos?

Dos Ojos is located between Tulum and Playa del Carmen, just off Highway 307:

📍 20 minutes from Tulum
📍 40 minutes from Playa del Carmen
📍 5–10 minutes from the entrance gate to the cenote

The cenote is well-marked, easy to access, and perfect for both snorkelers and divers.

How Big is the Dos Ojos Cave System?

The Dos Ojos cave system was once mapped as its own separate system, but in 2018, explorers confirmed its connection to Sistema Sac Actun, making it part of the longest underwater cave system in Mexico.

✔ Total surveyed length: 378 km (235 miles)
✔ Connected to over 100 cenotes
✔ Includes famous sites like The Pit

This connection makes Dos Ojos not just a cenote—it’s a gateway to a vast underground world.

Why Dive in Cenote Dos Ojos?

For open water divers, Cenote Dos Ojos is the perfect introduction to cavern diving. The dives are:

✔ Shallow (max 10m/33ft)
✔ Crystal clear with over 100m visibility
✔ Well-lit, making it great for first-time cavern divers
✔ Safe, with permanent guidelines and large spaces

The two main dive routes here are the Barbie Line and the Bat Cave, each offering something completely different.

What Can You See at Dos Ojos?

🌞 Sunlight Beams – Light floods the cenote, creating an unreal atmosphere.
🪨 Massive Rock Formations – Huge stalactites and stalagmites that took thousands of years to form.
🐠 Fossils & Hidden Passages – Ancient marine fossils embedded in the limestone.
🏛️ Spacious Caverns – Wide, open tunnels perfect for a relaxed, scenic dive.

Dos Ojos Diving Routes

Dive One – The Barbie Line

✔ Best for beginners
✔ Lots of light and open spaces
✔ Big rock formations and giant tunnels

This 45-minute dive starts with a swim-through between the two cenotes, following a large open tunnel where sunlight filters through from both sides. In the center, massive rock columns rise from the floor, giving the impression that they’re holding up the cave ceiling.

The dive stays within the cavern zone, meaning you’ll always be able to see natural light. You’ll swim past huge stalactites, stalagmites, and ancient fossils, with incredible visibility.

At the halfway point, you’ll spot the famous Barbie Doll, an unusual marker that gives the dive its name. From here, the route loops back slightly deeper and darker, making for a fun, varied experience.

Dive Two – The Bat Cave

✔ More enclosed & atmospheric
✔ Darker, with stunning formations
✔ Floating air pockets where bats live

This dive is a bit more adventurous—it’s still within the cavern zone, but it feels more like cave diving. The Bat Cave circuit takes you through:

1️⃣ The Big Columns & Open Water Area – A quick pass through the first cenote, where light pours into the tunnels.
2️⃣ The Bat Cave Chamber – A spectacular enclosed cave, where you’ll surface inside an air pocket filled with bats. Many snorkelers paddle here, but only divers get to see the full formations beneath the surface.
3️⃣ The Green Room – A dark, eerie chamber lit only by a faint green glow from lily pads above. This is where you’ll see some of the best stalactite formations in Dos Ojos.

While not as bright as the Barbie Line, the Bat Cave dive is a favorite among divers, thanks to its incredible formations and mysterious, atmospheric feel.

When Was Dos Ojos Discovered?

✔ First explored by cave divers in the 1980s
✔ Connected to over 100 cenotes
✔ In 1996, explorers discovered The Pit, reaching depths of 119m (390ft)

But of course, the Maya civilization knew of these cenotes long before modern explorers arrived. These waters have been a source of life, ritual, and mystery for thousands of years.

Can Anyone Dive at Dos Ojos?

Yes! If you have a PADI Open Water certification (or equivalent), you can dive in the cavern zone of Dos Ojos.

📌 No cave diving certification is required—these are guided cavern dives.
📌 Max depth: 10m (33ft)
📌 Required certification: Open Water (any agency)

If you want to dive deeper into the system, technical cave diving training is required.

Dos Ojos FAQ

How do I book a dive at Cenote Dos Ojos?

👉 Easy! Book your cenote dive here

Can I snorkel in Dos Ojos?

Yes! The shallow sections of Dos Ojos are perfect for snorkeling, with crystal-clear water and rock formations visible from the surface.

What’s the water temperature in Dos Ojos?

25°C / 77°F year-round. A 3mm wetsuit is recommended.

How long does each dive last?

40–45 minutes per dive, with a surface interval between dives.

Is Dos Ojos good for beginner divers?

Absolutely. The Barbie Line is one of the best cenote dives for beginners due to its large spaces and bright natural light.

Final Thoughts – Why Dive Dos Ojos?

Cenote Dos Ojos isn’t just one of the most famous cenotes in Mexico—it’s an unforgettable diving experience. Whether you’re a first-time cenote diver or a seasoned explorer, the Barbie Line and Bat Cave dives offer two completely unique experiences in one place.

✔ Unreal visibility
✔ Sunlight beams & rock formations
✔ Shallow, safe, and great for all levels

👉 Book Your Dive at Cenote Dos Ojos Today

The Pit & Dos Ojos

Tours, Advanced Certified

Tour Details

Cenotes:

The Pit
Dos Ojos

Dives: 2

Difficulty: Intermediate

Suitable for: Advanced

Features:

Stalactites & Stalagmites
Light Effects
Halocline

Price: $220

Angelita & Car Wash

Tours, Advanced Certified

Tour Details

Cenotes:

Angelita
Car Wash

Dives: 2

Difficulty: Hard

Suitable for: Advanced

Features:

Hydrogen Sulfide Cloud
Light Effects
Underwater Life

Price: $230 USD

The Pit & Dos Ojos

Tours, Advanced Certified

Tour Details

Cenotes:

The Pit
Dos Ojos (Barbie Lie & Bat Cave)

Dives: 3

Difficulty: Intermediate

Suitable for: Advanced

Features:

Stalactites & Stalagmites
Light Effects
Halocline

Price: $260 USD

Dos Ojos

Tours, Open Water Certified

Tour Details

Cenotes:

Dos Ojos

Dives: 2 (Barbie Line & Bat Cave)

Difficulty: Easy

Suitable for: Open Water

Features:

Rocks
Light Effects
Stalactites & Stalagmites

Price $200 USD

Cenote Diving in Tulum – The Ultimate Guide to Diving in Mexico’s Crystal-Clear Sinkholes

Cenote Diving, Best

Introduction

Cenote diving in Tulum is one of the most extraordinary scuba diving experiences in the world. These natural sinkholes, formed over thousands of years, offer crystal-clear visibility, stunning stalactites and stalagmites, and breathtaking light effects that create an otherworldly underwater adventure.

Unlike ocean diving, cenote diving takes place in freshwater caverns and caves, where you can witness haloclines (the blending of salt and freshwater), ancient rock formations, and even submerged Mayan artifacts. Whether you’re a certified open-water diver exploring cavern zones or an advanced cave diver navigating Mexico’s extensive underground river systems, Tulum’s cenotes provide an unforgettable experience.

In this guide, you’ll learn everything you need to know about cenote diving in Tulum, including:
✔️ What cenotes are and why they’re unique
✔️ The difference between cenote diving and cave diving
✔️ What to expect when diving in Mexico’s cenotes
✔️ Essential cenote diving equipment and safety guidelines

Cenotes are Mexico’s hidden underwater treasure—let’s dive in!

What Are Cenotes?
What Is Cenote Diving?
What Is Cave Diving?
What You’ll See While Cenote Diving
- Stalactites and Stalagmites
- The Halocline Effect
- Incredible Light Beams
- Ancient Fossils and Artifacts
Equipment for Cenote Diving
Specialized Equipment for Cave Diving
Is Cenote Diving Safe?
FAQ – Cenote Diving in Tulum

What Are Cenotes?

Cenotes are natural sinkholes formed by the collapse of limestone bedrock, exposing the underground rivers that run beneath the Yucatán Peninsula. These formations are part of a vast subterranean water system, once considered sacred by the Maya civilization.

Tulum and the surrounding areas have thousands of cenotes, ranging from open-air pools to deep caverns with stalactites, stalagmites, and crystal-clear water.

👉 Want to learn more about cenote history and geology? Click here.

What Is Cenote Diving?

Cenote diving is a freshwater diving experience in the caverns and caves of Mexico’s Yucatán Peninsula. Unlike ocean diving, cenote diving features exceptional visibility, minimal currents, and stunning rock formations.

Dives take place in caverns (where natural light is still visible) or caves (for trained technical divers). Each cenote offers a different underwater landscape, making cenote diving one of the most varied and visually striking experiences for divers.

What Is Cave Diving?

Cave diving is an advanced form of cenote diving that takes divers beyond the cavern zone and into fully enclosed underwater cave systems. It requires specialized training, redundant air supply systems, and advanced navigation techniques.

Differences Between Cenote Diving and Cave Diving:

Cenote Diving (Cavern Diving): Always within sight of natural light and open to recreational divers.
Cave Diving: Requires full cave certification, allowing divers to explore the extensive underwater tunnels of Tulum.

👉 Learn more about cave diving training and safety here.

What You’ll See While Cenote Diving

Stalactites and Stalagmites

Cenotes are decorated with incredible rock formations that took thousands of years to develop. Stalactites (hanging from the ceiling) and stalagmites (rising from the floor) create breathtaking underwater structures.

The Halocline Effect

A halocline is a visual distortion that occurs when freshwater and saltwater mix in a cenote. When you pass through this layer, the water appears blurred or mirrored, creating a surreal experience.

👉 Learn more about haloclines and where to see them here.

Incredible Light Beams

Some cenotes have spectacular natural light effects, where sunlight pierces through small openings, illuminating the water in shades of blue and green. Cenotes like The Pit and Dos Ojos are famous for these cathedral-like light beams.

Ancient Fossils and Artifacts

Many cenotes hold prehistoric fossils, ancient Mayan pottery, and even skeletal remains. These discoveries make cenote diving a mix of exploration, history, and geology.

Equipment for Cenote Diving

Cenote diving requires specific gear to ensure safety and visibility in cavern environments. While standard dive equipment is used, a dive light is essential due to the overhead environment.

✅ Regulator & Alternate Air Source – A reliable system to ensure redundant air supply.
✅ Buoyancy Control Device (BCD) – Helps maintain neutral buoyancy to avoid disturbing sediment.
✅ Full Wetsuit (3mm to 5mm) – Cenote water temperatures range between 24–26°C (75–78°F).
✅ Primary Dive Light – Required for proper visibility in darker cenote sections.

Specialized Equipment for Cave Diving

For those venturing into cave diving, additional safety equipment is required due to the overhead environment and lack of direct access to the surface.

✅ Primary Dive Light – A high-powered light is essential for navigating the darkness.
✅ Backup Lights – Two additional lights are required in case of failure.
✅ Reel & Guide Line – Used for navigation, ensuring a clear path back to the entrance.
✅ Sidemount Configuration – Common in cave diving for better streamlining in tight spaces.

👉 Want a detailed guide to cave diving equipment? Click here.

Is Cenote Diving Safe?

Yes! Cenote diving is very safe when following proper guidelines and diving with an experienced guide. Although cenotes are overhead environments, diving is conducted in controlled, well-mapped areas.

Key Safety Guidelines:

✔️ Always dive with a certified cenote guide.
✔️ Follow the “rule of thirds” for air consumption.
✔️ Maintain neutral buoyancy to avoid stirring up sediment.
✔️ Respect the cenote environment—avoid touching formations.

FAQ – Cenote Diving in Tulum

Do I need special certification to dive in cenotes?

No, most cenote diving is available to certified Open Water divers. However, cave diving requires advanced certification and specialized training.

How deep are cenotes?

Cenotes typically range from 5 to 30 meters (16 to 98 feet) deep, though some, like Angelita, can reach depths of over 60 meters (197 feet).

What’s the water temperature in cenotes?

Cenotes maintain a constant temperature of 24–26°C (75–78°F) year-round, making them perfect for diving in any season.

Is cenote diving affected by weather?

No, since cenotes are protected underground environments, they remain unaffected by rain, waves, or currents, ensuring excellent visibility regardless of the weather.

What marine life can I see in cenotes?

While cenotes aren’t home to large marine animals, you may encounter freshwater shrimp, small fish, and even blind cavefish in certain cenotes.

Are cenotes dangerous?

Cenote diving is safe when proper training, safety procedures, and an experienced guide are in place. Always dive with a professional to ensure a secure and enjoyable experience.

Final Thoughts

Cenote diving in Tulum is a breathtaking experience, offering unmatched visibility, stunning rock formations, and a unique insight into the Earth’s history. Whether you’re a beginner exploring the cavern zones or a certified diver ready for cave exploration, cenotes offer something truly unforgettable.

👉 Discover the Best Cenotes for Diving in Tulum Here.

Casa Cenote & Car Wash

Tours, Open Water Certified

Tour Details

Cenotes:

Casa Cenote
Car Wash

Dives: 2

Difficulty: Easy

Suitable for: Beginners

Features:

Marine Life
Light Effects
Halocline

Price: $220 USD

Cenotes in Mexico – How They Were Formed & Their Ancient History

Cenote History

Why Are There So Many Cenotes in Mexico?

Cenotes are natural sinkholes formed by the slow erosion of limestone rock. The Yucatán Peninsula is home to over 6,000 cenotes, making it the cenote capital of the world. But why are there so many here?

The Science Behind Cenote Formation

✔ The Yucatán Peninsula is made of porous limestone, which allows rainwater to seep through, slowly dissolving the rock over thousands of years.
✔ Over time, underground rivers carved vast cave systems beneath the surface.
✔ When cave roofs became too thin, they collapsed, creating cenotes—natural access points to the underground water system known as the Great Mayan Aquifer.

Cenotes Are Mexico’s Underground Water Veins

Cenotes and their vast cave systems transport fresh water beneath the jungle, much like the veins of the Earth, filtering rainwater and nourishing the lush forests above. Without cenotes, there would be no freshwater in the Yucatán!

What Created Cenotes?

Cenotes are created when cave passageways become so large that the roof collapses. Most cenotes have a round opening, with a pile of fallen rocks in the middle and clear water surrounding it.

But this process didn’t happen overnight—it took millions of years of geological changes, rising and falling sea levels, and one major cosmic event…

☄️ The Meteor That Changed Everything

66 million years ago, a 10-kilometer-wide asteroid crashed into the Yucatán Peninsula, creating the Chicxulub Crater. This impact:
✔ Shattered the limestone bedrock, creating fractures that allowed water to flow underground.
✔ Triggered global climate change, wiping out the dinosaurs and leading to extreme ice ages.
✔ Helped shape the underground rivers, setting the foundation for cenote formation.

👉 The Yucatán’s cenotes are a direct result of the same impact that ended the dinosaurs!

How Were Cenotes Formed? A Step-by-Step Breakdown

1️⃣ Millions of Years Ago – Limestone Formation

The Yucatán Peninsula was once a shallow sea, covered by coral reefs and marine life.
Over time, dead coral, shells, and marine creatures compacted, forming a thick layer of limestone rock.

2️⃣ The Meteor Impact (66 Million Years Ago)

The Chicxulub asteroid impact shattered the limestone, creating cracks and fissures in the Earth’s crust.
These fractures allowed rainwater to seep deep underground, forming the Great Mayan Aquifer.

3️⃣ Ice Ages & Underground River Formation

Over millions of years, acidic rainwater dissolved the limestone, creating massive underground caves and tunnels.
During ice ages, when sea levels were low, these caves remained dry, allowing stalactites and stalagmites to form.

4️⃣ Cave Collapse & Cenote Creation

As sea levels rose and fell, underground caves flooded and emptied multiple times.
The cave ceilings weakened over time and eventually collapsed, creating cenotes.
Water from the Great Mayan Aquifer filled the cenotes, making them oases of crystal-clear freshwater.

👉 Cenotes are essentially “windows” into the world’s largest underground river system!

What Are the Different Types of Cenotes?

Cenotes are classified based on their age and formation stage:

Cenote Type	Formation Stage	Example
Open Cenote	Fully collapsed, like a natural swimming pool	Cenote Azul
Semi-Open Cenote	Partially collapsed, with both open-air and cave sections	Cenote Dos Ojos
Cave Cenote	Entirely enclosed, accessible through a cavern entrance	Cenote El Pit
Collapsed Cenote	A cenote that has eroded into a lagoon	Laguna Bacalar

Each type of cenote offers a unique experience, from swimming and snorkeling to cave diving deep into the Earth’s hidden world.

What Does “Cenote” Mean?

The word cenote comes from the Maya term “Tzonot,” meaning “sacred well”. The ancient Maya saw cenotes as portals to Xibalba—the underworld.

In English, a cenote is also called a “sinkhole,” but the term doesn’t fully capture their beauty and cultural importance.

Why Were Cenotes Important to the Maya?

For the Maya civilization, cenotes were the source of life and the entrance to the afterlife.

✔ Freshwater Supply: With no rivers in the Yucatán, cenotes provided the only drinking water.
✔ Sacred Ritual Sites: The Maya made offerings to Chaac, the rain god, in cenotes.
✔ Human Sacrifices: Archaeological evidence suggests some cenotes were used for ceremonial sacrifices.
✔ Burial Grounds: Some cenotes contained Maya artifacts, pottery, and human remains.

👉 The famous Sacred Cenote at Chichén Itzá is one of the best examples of a cenote used in Maya rituals.

What Can You See Inside a Cenote?

Cenotes are time capsules preserving ancient fossils and formations:

✔ Fossils of prehistoric marine life – Proof that the Yucatán was once under the sea.
✔ Stalactites & Stalagmites – These formations only grow in dry caves, proving sea levels were lower in the past.
✔ Haloclines – A visible mix of freshwater and saltwater found in deep cenotes like El Pit.
✔ Blind Cave Fish & Unique Aquatic Life – Some cenotes have fish that evolved to live without eyesight!

Best Cenotes in Mexico for Diving & Snorkeling

Cenote	Location	Best For
Gran Cenote	Tulum	Snorkeling
Dos Ojos	Tulum	Cavern Diving & Snorkeling
El Pit	Tulum	Deep Diving
Cenote Angelita	Tulum	Underwater Hydrogen Sulfide Cloud
Cenote Azul	Playa del Carmen	Open Cenote Swimming
Cenote Ik Kil	Chichen Itza	Touristic Open Cenote
Cenote Calavera	Tulum	The “Temple of Doom” Cave Diving
Cenote Car Wash	Tulum	Cavern Diving & Photography

Each cenote offers something unique—whether it’s swimming in open cenotes, snorkeling with fish, or diving into deep caverns.

Experience the Magic of Mexico’s Cenotes

Whether you’re interested in cenote diving, snorkeling, or learning about their ancient history, the cenotes of Mexico are a must-visit natural wonder.

👉 Book a Cenote Adventure Today
📩 Have questions? Contact Us

Cenote Diving & Snorkeling – What to Expect

Snorkeling in Cenotes

✔ No experience needed—just bring a mask and swim!
✔ Crystal-clear water with over 100m visibility.
✔ See stalactites, fish, and turtle life up close.

👉 Book a Cenote Snorkeling Tour

Cenote Diving (For Certified Divers)

✔ Explore hidden caverns with amazing rock formations.
✔ Swim through haloclines where freshwater and saltwater mix.
✔ Visit ancient fossilized coral formations inside the caves.

👉 Book a Cenote Diving Adventure

Cave Diving

✔ Go beyond the light zone into the deep underground tunnels.
✔ Follow permanent guide lines through spectacular passageways.
✔ Experience the thrill of true cave exploration.

👉 Get Cave Diving Certified

FAQs About Cenotes

1. Can anyone swim in a cenote?
Yes! Most cenotes are perfect for swimming and snorkeling, even if you’re not a diver.

2. How deep are cenotes?
Cenote depths range from shallow pools (2-5m) to deep sinkholes over 100m (like El Pit).

3. Do cenotes have fish?
Yes! Many cenotes have small fish, turtles, and even blind cave fish.

4. Are cenotes safe?
Yes, but it’s important to respect the environment—wear no sunscreen, be mindful of slippery rocks, and always dive with a guide if entering caves.

The Pit Cenote – The Deepest Cenote Dive in Mexico

The Pit, Cenote, Cenote Diving

What is The Pit Cenote?

The Pit Cenote is one of the most breathtaking and legendary cenotes in Mexico. Located near Tulum, this deep, vertical sinkhole offers an unforgettable dive experience, featuring:

✔ Laser-like light beams piercing the water
✔ A dramatic 119m (390ft) deep cave system
✔ A mesmerizing hydrogen sulfide cloud at depth
✔ Incredible stalactites and ancient rock formations

This is a must-dive cenote for advanced divers looking for a mind-blowing experience.

Where is The Pit Cenote?

📍 Location: Between Tulum and Playa del Carmen, just off Highway 307.
📍 Travel Time: 20 minutes from Tulum, 40 minutes from Playa del Carmen.
📍 Entrance: Follow the Dos Ojos Cenote sign, then take the jungle road to The Pit.

How Deep is The Pit Cenote?

The Pit has been explored to a maximum depth of 119m (390ft). However, for recreational divers:

✔ Max depth for Advanced Open Water divers: 40m (130ft).
✔ Technical divers with training can go deeper with special permission.

The deeper you go, the more surreal the experience becomes.

How Can I Dive The Pit?

To dive The Pit Cenote, you need:

✔ Advanced Open Water certification (or equivalent).
✔ Comfort with deep diving.
✔ Good buoyancy control.

👉 Want to dive The Pit? Book your dive here.

The Best Time to Dive The Pit

You can dive The Pit Cenote year-round, but for the best light show, timing matters:

✔ Summer (May–August): Best light beams due to the sun being directly overhead.
✔ Winter (December–February): Sunlight hits at an angle, so the best time is earlier in the day.
✔ Peak conditions: Around midday on the summer solstice, when the sun is at its highest.

The clearer the sky, the better the laser beam effect—so sunny days are ideal.

What Can You See While Diving The Pit?

Diving The Pit is like entering another dimension. Here’s what makes it so extraordinary:

1️⃣ The Light Beams – A Spectacular Natural Show

The light beams at The Pit are legendary.

☀️ Sunlight enters through the narrow opening, creating intense, laser-like beams that shoot down into the cavern.
💫 Ripples on the surface bend the light, creating dancing, shifting beams that feel like something out of a sci-fi movie.
📷 Photographers and videographers love it—it’s one of the most visually stunning underwater experiences in the world.

👉 Best time for the light beams? Midday in summer.

2️⃣ The Halocline – A Mirage Underwater

At around 12–15m (40–50ft), you pass through a halocline—the layer where freshwater meets saltwater.

🔹 Light bends and distorts—making the world look like a wavy mirage.
🔹 Your vision momentarily blurs, but as you descend below the halocline, the clarity returns.

It’s like diving through a portal into another world.

3️⃣ The Hydrogen Sulfide Cloud – Like a Ghostly River

At 30m (100ft), we reach the hydrogen sulfide cloud.

💨 It looks like a thick layer of fog, floating in the water.
🦴 Beneath it, hidden from light, lie ancient bones and artifacts.
💀 Archaeologists have found human and animal remains—evidence of a time when this cenote was dry.

Swimming through the ethereal white cloud feels surreal, as if you’re floating through mist.

👉 The best way to experience it? Descend into the cloud, then slowly rise above it.

4️⃣ The Stalactites & Ancient Rock Formations

At the back of The Pit, we find:

✔ Giant stalactites hanging from the ceiling.
✔ Stalagmites rising from the floor, proving the cenote was once dry.
✔ Mercury-like air pockets on the ceiling, shimmering in the light.

This is a journey through time—a glimpse into Earth’s prehistoric past.

5️⃣ The Multi-Level Dive Experience

🔹 Deep Section (30–40m/100–130ft): Descend through the hydrogen sulfide cloud, explore the vast cavern, and feel the scale of The Pit.
🔹 Mid Section (15–25m/50–80ft): Hover near the rock formations and see the remains of ancient artifacts.
🔹 Upper Section (5–12m/15–40ft): Enjoy the halocline, play with light refraction, and get the best views of the laser beams.

A well-planned dive maximizes the experience at every depth level.

Why The Pit is One of the Best Dives in the World

🌎 I’ve worked in diving all over the world, and I can confidently say:

👉 The Pit Cenote is one of the most incredible dive sites anywhere.

Unlike ocean dives, where you expect to see coral and fish, The Pit challenges expectations.

✔ It’s about light and shadows.
✔ It’s about science and history.
✔ It’s about time and space.

The Pit makes you feel small—reminding you that you’re diving through a place millions of years old.

Everyone who dives The Pit comes up amazed. Some people are even deeply moved—touched by the same magic I experience every time I dive here.

Ready to Dive The Pit Cenote?

The Pit Cenote isn’t just a deep dive—it’s an adventure through time, light, and space.

✔ Experience the famous light beams.
✔ Descend through the hydrogen sulfide cloud.
✔ See ancient formations millions of years old.

📍 Requirements:
✔ Advanced Open Water Certification
✔ Good buoyancy control
✔ Love for adventure

👉 Book Your Pit Cenote Dive Here

Halocline – Where Fresh Water and Salt Water Meet is called a Halocline

Cenote Diving, Halocline

What is a Halocline?

Where Fresh Water and Salt Water Meet is called a Halocline. A Halocline is defined as, the level where the amount of dissolved salt changes sufficiently to be able to see. We see this phenomenon in the caves of the Yucatan while scuba diving.

What does Halocline mean?

The word comes from Greek. Halo means salt, and Cline means slope or graduation. It is where the higher fresh water, that has fallen as rain, meets the lower salt water, that comes in from the sea.

What’s the difference between a Thermocline and a Halocline?

A thermocline is a change in temperature, whereas a Halocline is a change in salinity, in the level of water. There is a change in temperature in a halocline. In the cenotes, in Mexico, the temperature rises a degree or two as we descend into the salt water layer.
At the end of a long cave dive, if we spend time in the nice warm salty water, it can feel quite cold going back up into the colder fresh water.

What is the Mixing Zone?

When Salt and Fresh Water mix it is called a mixing zone. Sometimes in a cave system, we see two Haloclines at different levels. So there is a higher fresh water level. Then brackish water in the Mixing Zone. Then salt water in the lower level.

What does a place where Fresh Water meets Salt Water look like?

Salt makes the water denser so light bends as it passes from one to the other. When it’s undisturbed we can see waves rising and falling caused by the slightly faster flowing fresh water. It looks like another surface to the water. It’s best to shine your light across the layer to see it better. The refraction works better.
When we dive through it the salt water and fresh water mix together and it all gets very blurry. This is different from a mixing zone because it hasn’t fully mixed yet. Light is massively distorted and the effect is like a mirage in the desert which can be a little challenging sometimes in a cave.

To get the best visual effect we position ourselves with our eyes just on the Halocline. The salt water is warmer so we have a warm body but a cold head. It looks crazy, stunning. Words cannot fully describe the beauty. As we rise and fall gently with each breath, we slowly propel ourselves through the layer keeping it fresh and clean. We see concentrated horizontal beams of light and the rocks behind distort as if in a hall of mirrors at a fairground.

Are Cenotes Fresh or Salt Water?

It depends on how deep and how close to the sea they are. A shallower cenote further inland is likely to be fresh water, but the deeper you go down into the cave the higher the chance of encountering the salt water. Having said that, the closer to the sea you get the bigger the mixing zone so there is more chance of brackish water.

« Older Entries