Cenote Sac Aktun

Sac Aktun, meaning white cave in Maya, but better known as Grand cenote, is a collapsed roof cenote offering great snorkeling and both fantastic cavern and cave diving.

This is the most famous of the cenotes near Tulum and a real gold mine for its owner, who happily cashes in on the many tourists who visit it. Come early or in late afternoon, and you’ll have it mostly for yourself.

The old ladders have been replaced by more trusty wooden stairs and a big platform allows easy entry and exit into the cool crystal clear fresh water. I’ve seen some daredevil swimmers jump in from the top, but a giant step entry from 6m high is definitely not a good idea. The water isn’t quite deep enough and your precious life-support gear, not to mention your soft body, might not appreciate the impact.


Sac Aktun’s walls are almost white, as its Mayan name implies and they reflect a lot of light. The main cavern area allows snorkelers to swim in pretty far, which also means the surface and free air is never too far away for cavern divers, who can enjoy the wonderful feeling of diving between big drooping stalactites, take a peek into beautifully decorated side rooms and get an insight of what cave diving is all about here in Yucatan. For a true taste, Dos Ojos, further up north, is highly recommended. Grand cenote also boasts a big cavern area on one of its sides, where the ceiling slopes down and meets the floor at about 12m.

With an average depth of 7m and a maximum depth not exceeding 14m, the Sac Aktun system allows for long cave dives indeed, without immediate need for extra stage tanks, except for truly extended dives into the far reaches of this seemingly endless cave system, connecting several cenotes, in which case you’ll also need several jump reels and an excellent visual memory. The main line ends at cenote Ho Tul, but not the cave.

The usual little cenote fish are abundant in Grand cenote too, as well as the lazily meandering catfish. Turtles can be spotted in the open water area among the plants or even dozing between the stalactites, but are rather weary of too much attention, so give them a break.

Cenote Vaca Ha

This used to be a very small pool of tannic acid brownish water, with some reeds on one side. Just big enough for one diver to get in at a time, down a short wooden ladder, and disappear beneath the earth.


The cenote’s name is Maya for cow water, after the unlucky bovine I guess, which in its thirsty haste must have stumbled in it, its bones still discernible among the fossil encrusted rocks covering the bottom.

Some time ago the landowner had the pool enlarged somewhat. In the hope of getting a more attractive and lucrative swimming hole like the neighboring Aktun Ha. The scheme didn’t quite work out. But it’s still a great portal to the amazing world of the flooded caves.


Initially the cave is very low ceilinged and some crawling is required, but soon it opens up in a great room with vast columns and pillars, after which it turns into a long tunnel. At some point the tunnel widens up into a low chamber, where the halocline – the boundary between fresh and salt water, here at 21m – is clearly visible, as if you were flying over a lake.

Due to the deeper average depth this usually is a deco dive. With nitrox however, long deco times can be reduced if not avoided.

Cenote Aktun Ha

Aktun Ha, meaning water cave in Maya, also known as Carwash, lays less than 15m from the side of the road. Supposedly taxi drivers used to wash their cars here, from where its nickname.

Since the discovery of its cavern and cave system, the cenote has become a popular tourist attraction. There’s a changing hut and restrooms, besides very practical wooden tables for gearing up. A wooden platform and stairs allow for easy entry and exit. Both the open water area and cavern zone are an ideal training and skills review ground.

At first sight the cenote is nothing more than a pool of not very inviting greenish water, surrounded by the typical low Yucatan jungle. The water’s color is due to microscopic algae that reduce visibility in the upper 3m to nearly zero. Below that however, the water becomes crystal clear and noticeably cooler. This green algae bloom, not present during the colder winter months, adds a lot to the cenote’s ancient and mysterious atmosphere.

As soon as one jumps in, dozens of hungry little fish form an inquisitive escort, a real hunting party that seldom relents before the end of the dive, following the diver all the way into the cave and back, looking for an easy caught meal of helpless tiny cave creatures caught in the dive light’s merciless beam.

The bottom of the pool, at 5m, is easily stirred up by careless fins, so watch your step. The entrance to the upstream cavern zone is partially obstructed by fallen trees. The branches of which form a perfect spot for a first tie off of the mandatory guideline.

As one enters, little is visible at first, but as the eyes slowly adjust to the twilight, the cavern’s great hall seems to grow bigger, the rock-strewn bottom dips down to 18m and large ancient stalactites loom out of its gaping void.

In the back, where the floor rises up again to about 9m, a sturdy column seems to support the whole ceiling. Behind it, past the no nonsense warning sign: "Stop! Prevent your death! Do not dive further unless cave trained.", several thinner columns of joined stalactites and stalagmites decorate the low chamber, which lead the knowledgeable cave diver deeper into the cave, away from the last faint glow of daylight.

A lonely catfish seems to patrol the area where the main line starts. Once well within the cave, it is not uncommon to see the white almost translucent ghost fish here, or even a shrimp scurrying away on some of the silt slopes.


The main line leads to Adriana’s beautifully decorated room. Before getting that far, it is also possible to do a side jump through a narrow tunnel to the Crystal Palace and the famous Room of Tears.

No matter how fantastic the cave, it is always a magical moment, when near the end of the dive, after an hour or more in darkness, one slowly returns back into the daylight. This is especially true for Aktun Ha, whether the light is tinted misty green by the algae cloud or not, the view out is always fabulous.

A couple of colder nights is all it takes to totally clear up the cenote’s open water area, and this allows one to check out the pool’s edges for the many fresh water turtles living here. If lucky you might even spot a small alligator at the water’s edge, warming up in the sun, floating around like a log or even slowly snaking its way around underwater. I’ve also seen a diving duck here in the past, speeding through the water like a torpedo.

Cenote Kalimba

Kalimba is a dry holy cavern, with a small altar to one side. A small shallow pool inside gives access to a whole other spiritual world. The underwater chambers and passages are low ceilinged but beautifully decorated with fields of fragile stalactites.


This is cave crawling at its best, with a couple of narrow restrictions requiring some careful maneuvering to squeeze through. As in most caves, several jumps can be made to explore interesting and less traveled side passages.


The Kalimba system connects to the Sac Aktun system, allowing a great traverse dive from one to the other. That is, if you know the way and have done the necessary preparatory work.

Cenote Calavera

Entrance used to be free here, but it was also rather risky to leave your car unattended by the side of the road. At least now there’s a small table for gearing up, and the car is being watched.


After a 100m walk through the Yucatan jungle, under a 30°C hot sun, in a 7mm neoprene wetsuit, carrying about 50kg of cave diving gear, you kind of get rather hot and steamy.

You’re then faced with a hole in the ground and a 3m jump into Calavera, supposedly meaning skull for the gaping mouth-like hole with two smaller eye-like ones around it, but better known as the Temple of Doom.

Wings pumped up you take a couple of deep breaths and apprehensively (the first time) or brazenly (the next times) step forward – hoping your gear will take it. The subsequent big splash causes the resulting waves to splatter noisily against the cenote’s walls, waking up the few bats that call it their home.

There’s nothing like feeling the fresh 24°C water flood your suit and cool you down. Soon the peace is restored as you prepare to submerge. Buzzing bloodthirsty mosquitoes clearly audible in the ominous silence.


Like every cenote, this one has its own character, in this case a slightly somber one. Due maybe to the rather small hole and surrounding trees filtering most of the light, except around noon, when sun rays break through the water’s surface and delight the blessed diver with a spell binding show.

Calavera is a dome like cavern, with a mount of debris in its middle. About 10m deep, along the circular wall, there’s a fossil layer of coral bits and shells, witnesses of a time long gone by, when Yucatan was part of the ocean bottom.

The two parallel cave entrances are both located below the halocline, here at around 12m – where fresh and salt water meet but do not willingly mix. When both are inevitably disturbed by the first diver, this causes very blurry vision for the following divers, until they sink further down fully into the warmer and heavier salt water.

The main tunnel, known as the Madonna passage, is bright bluish white, with a lone brownish statue, the Madonna, halfway in. The water flow’s slow but constant erosion really has done some strange things here with the soft calcareous walls, creating weird sculptures here and there.

It’s possible to do two circuit dives here, after careful preparation and attentive planning by all team members, as the multiple T junctions invariably cause some confusion otherwise. Continuing past the two circuit branches, the tunnel opens up into a great room, with a big stalactite known as the Fang.

Getting out of Calavera is a bit harder than getting in. But the steep metal ladder helps.

Cenotes

There are no surface rivers to speak of in Yucatan. All the rainwater filters through the porous limestone and flows underground.

Over the years this constant erosion created vast systems of caves with wonderful decorations of stalactites and stalagmites, from fields of young soda straws to solitary old columns. Then as the water level rose, these caves were flooded. Cenotes are openings to these forgotten worlds, usually in places where the cave's roof collapsed.

Located between Tulum and Coba are five of these cenotes.

Aktun dive center

Located at the entrance of town, on the crossroad leading to the beach, the center, Coba and Playa Del Carmen, Aktun dive center & hotel El Meson are indeed very conveniently placed for cave diving the nearby cenotes - most of them less than a 15' ride away.


The fan rooms are basic but decent enough, though not very charming and rather noisy due to the heavy traffic driving by all day and night.


Besides Gunnar Wagner, the owner and IANTD instructor-trainer, there are two full-time instructors at the moment and one driver-handyman. Plus the hotel management and staff. And they have two jeeps, two suburban vans, two compressors, lots of tech gear for rent and several UW scooters for people in a hurry.

I used to work here as a dive guide & instructor, so this will always be a special place for me...

Tulum

Tulum has changed a lot over the last six years... From a laid back travelers bus transit stop, to a wannabe bustling tourist town.

The good thing about that is that you can find almost anything now in the local mini supermarkets and pharmacias. There's even a bank now, two ATMs and several money exchange counters (open all week). Everything is pretty much located along the main street running through town.


Basic rooms in town go for 25-45 USD and twice that much along the beach. A typical meal in a Mexican eatery costs from around 20-25 Pesos all the way up to 50-75 Pesos for meat and shrimp dishes. Add 10-15 Pesos for a fruit drink. Tourist restaurants charge from 60 to 180 Pesos for a meal. For great Italian pizzas, "La Nave" is the place in town! I can recommend the "Capricciosa".


If you don't have a rental car, Tulum's "Tiburones" will be happy to charge you the tourist price for a ride in their white taxis. Tiburon is Spanish for shark, a name they try to live up to very hard.

[ note: all the rather blurry above land snapshots were taken with a Nokia 6230, whereas all the underwater photos were taken with a Sea&Sea MotorMarine IIex, with 20mm WAL and YS60 flash, using normal Fuji 100 ASA film ]