This was my last day of diving. I wanted to do a stage dive, going long. Hesitated a bit, but in the end decided to go upstream on the main line at Nohoch.

I have done this same dive last year, but Pietro, my dive guide at the time, was ultra-conservative, and swam at a very leisurely pace. It took us over an hour to get to Dinner's hole Cenote, and we turned the dive some 20 minutes later. I wanted to go deeper into the cave.

My intention of taking two extra 80cuft cylinders was dashed by lack of training. Even in open water I could see that managing 2 stages on the same D-rings was going to be a struggle. So we left one stage behind, and went in with only a single stage.

It took us 40 minutes to dinner's hole, and we weren't pushing. We kept going for another 40 minutes. Past the dinner hole, as noticed last year, the cave gets temporarily barren with less decorations. But it soon changes back to the usual magnificiency. Lots of gas pockets. I surfaced in one. I couldn't see any flying bats and decided to keep the regulator in my mouth.

This is a very shallow part of the cave. In places you do swim amongst the tree roots. When I turned on thirds we were close to the turnoff to the far point station.

On the return we did a couple of jumps after recalculating thirds. It's the good thing about diving independent gas stage supplies. When you get back to your stage, you can recalculate a third of your back gas and go side exploring without violating the thirds rule.

One of the jumps we did got us into a small zone of the cave so full of spelothems that I considered turning around for fear of braking something. Felt a bit like an elephant in a china shop. In the end I think I did pretty well. Tip toeing, so to speak, from stalagmyte to stalagmyte, left it as I found it.

On the second jump Steve's primary run out of battery. I have had the same problem with the halcyon charger. You really need to be very careful to make sure it doesn't give a false full charge. I usually replug it a few times to make sure all is well. No such problems with the Li-on Salvo set. Anyway, we called the dive at the end of that line. Dive duration: 3 hours and a half.

Nohoch Na Chich... full of secrets...

Diving amongst the tree roots

An air pocket seem from below... you can point your light at the surface and the shine will shimmer down like if coming from above. Quite beautiful.

Surfacing in an air (?) pocket

A decorated area in a side exploration off the main line.
Felt like an elephant in a china shop, but didn't break anything.

Return to the cavern area... daylight at last.

Next time I'll hit the gym with a little more frequency for a few months before coming. If I want to get into out-of-the way cenotes, long walks with 50 kgs on your back are required. Most of the really interesting sites are out of the way. The Pit is now more accessible but it's still a 250 meters walk. The Blue Abyss even further from where you can get to with a 4WD.

This is a unique place. Where caves are the most accessible. But it still pays to come prepared.

Partial Map of Sac Aktun

Today we visited Gran Cenote in the Sac Acktun system. This became the largest submerged system in the world when it was connected to Nohoch Na Chich by Steve, before being overtaken by Ox Bel Ha, further to the south, mid of this year, when previously unsurveyed passages were added to this system. They are roughly of the same size. About 160km. Put together, you could fit the whole A1 freeway from Porto to Lisbon, inside of these systems. That's how big they are.

The Gran Cenote is one of these pools where you find swimmers and snorkelers, although today it was not busy. It's a nice, tranquil place.

A split shot of the Gran Cenote water basin

First we dove Paso del Lagarto and Much's Maze. All wide open spaces, very white, pristine, monumental. Average depth 12 meters. Navigation here is complex. Several jumps, some 20 or 30 meters apart. If you don't know the cave it can be tricky to find the lines.

In December of 2004 there was a double fatility in here. 9 divers, split into two groups but sharing markers and lines, dove from Cenote Calimba in the direction of Cenote Box Chen. The group of 4 divers took a wrong direction decision on the return as pointed in the map above. They should have followed the red arrow but took the yellow arrow direction instead. They came all the way down the Paso del Lagarto line. At the end of the line they tried to find the Gran Cenote line. It's a long jump, and they couldn't find it. Gran Cenote or Cenote Hotul were just a few minutes away.

They tried to go back to Cenote Calimba. The other group had already removed the markers and lines having thought that the first group had already exited. 2 divers made it out with just 700 psi total left in their tanks. The other two run out of gas and their bodies were later recovered a hundred meters from the exit.

I took the camera on the first dive. The second dive, towards the Caverna de los Comillos and the restriction of La Boca, had even more complex navigation, so I decided to leave the camera behind. We had four jumps, first turning left into the shortcut to cenote Ho-tul, then back to the main line. Next we had to gap the cenote, and finally we had to jump from the Cuzan-Nah circuit to the Cavernas de los Colmillos line. It was a great dive. First time in this system but I feel like returning.

Some pictures from the first dive follow.

Steve entering the Paso del Lagarto

White decorations and walls

Some more pristine spleothems

On return, Gran Cenote becomes slowly visible

By coincidence I shot the same picture in Carwash twice with a 14 month interval. The picture of Steve entering the restriction on the floor after the jump off the mainline, was taken yesterday.

The next, of me exiting the same restriction, was taken in August of last year. You can see the result of human intervention. The works to clear land around luke's hope cenote (a hundred feet downstream!), resulted in the accumulated sediments that you can see.

This year / Last year

My dive today, after this forced hiatus, was in Carwash. I like to strike a compromise between doing new systems and passages and returning to favourite places. CarWash is an old friend.



I'm diving with Steve Bogaerts, probably the best cave diver in the world. At least that's what it seems to me. His knowledge his boundless, and has been exploring this area for some years now. His technique is not only just better, it's an order of magnitude better. I think I'm a reasonably fit diver. I can get my SAC rate to 12L a minute while swimming in no flow conditions. That's better than most. Well he can get it down below 6 liters per minute (I saw it in his gauge). That's better than 99% of what people do... when they are sleeping. I asked him what was the secret. Experience, Gym and Yoga seems to be the answer.

I woudn't hesitate to recommend him to anyone for guiding and training, if he is available. He is the explorer who was on the world news earlier this year when he connected Nohoch Nah Chich with Sac Actun and made what, at the time, was the biggest underwater cave in the world with about 160kms of surveyed passages.

His exploration stories are endless. His survival from a passage collapse, that left him in the wrong side of the collapse, deserves a book. Continuing the dive into the cave, he found a new Cenote that saved his life. However the return thru virgin jungle was not without its perils, so he decided to go back and try to dug out the collapse. Almost got stuck in falling debris and further collapse. Returned to the cenote. While trying to find his way overland almost collapsed from heatstroke. Finally he made it to the departing station and had to repeat the trip a few times before finally hauling all of his equipment back. He was exploring alone without a supporting team.

The odds of survival must have been minute. First finding an exit was sheer luck. Then that the entrance allowed him to exit was another lucky occurrence. I can just imagine seeing light in these kind of conditions just to find out that the exit is like dinner's hole in Nohoch, a sink hole, basically the inside of a cone. One could be there for a month before dying of hunger. Fresh water would be abundant, and hypothermia wouldn't set in if you could get yourself out of the water. Not nice.

He's been on BBC documentaries. And you can find him on youtube. This is an example:



But back to CarWash. Steve is a fast diver. So I had expectations of reaching deeper sections of the cave. Mike, one of my previous guides was also fast, but I didn't dive with him all of the time. The other guides took it ultra conservatively, slowing down for safety. As always this is always a compromise. You should never enter faster than you can exit. My marathon running however lets me keep a good pace for a few hours without slowing down.

Map of Carwash, first dive upstream in red, second dive downstream in brown

Steve had warned me that Luke's Hope cenote had construction working going on and thus the upstream section between the entrance and Luke's Hope was silty. Actually it wasn't silty. Visibility was not near zero. It was Zero Zero, like in zilch or nada. However knowing that it was temporary and that past Luke's hope it would clear up gave me some tranquility. It's however a special situation. Quite different from exiting the cave with eyes closed while training. You cannot loose the line. If you do, the stress level will go sky high until you find it again. And if you don't...

We didn't get all the way to dreamland as I intended. Called the dive on thirds.

The jump after luke's hope, down thru a restriction on the floor is always a great moment.

Back at Carwash!

Arriving in Cozumel... shock! a cruise ship is docked

Took the boat to Cozumel. Last time I was there was more than 10 years ago... it's all changed, a huge pier where cruise ships come to dock have generated an ecosystem of peddlers, shops, boutiques, starbucks and macDonalds that did nothing but make it unrecognizable.

I imagine that if you drive out of town, the island will have changed less...



My ears are getting better, but still too painful to dive. Luckily it's only external, so equalization is still possible.

Come rain or shine, I'll be diving tomorrow. With my camera.

Bacteria abounds in fresh water and the current humid conditions are an optimal breathing ground. I can just feel how cozy they must have found my ear canals... Drops, anti inflammatory, antibiotics and a quickly put together magical potion of vinegar and alcohol will hopefully allow me to return to diving soon.

In the meantime, it's beach time...

One year and a few months later I returned. Not a lot of time to blog so my trip is now 6 days old...




My very last dive, prior to this trip, was the one I logged below. It's amazing how much one forgets in 14 months. For the first few dives you are back to square one. Or zero. It's a conundrum difficult to break for someone living in Lisbon, short of hitting the swimming pool with doubles, stages and reels and frightening the swimmers out of the water.

I suspect that when my guide first saw me underwater, he sincerely wondered whether I had had any training whatsoever and I wasn't trying to fast track from the reefs of playa del carmen straight into cave diving.


I did not yet dare taking the camera with me. Took it easy in Chikin Ha, a cenote close to Playa, on the first day and in Taj Mahal on the second, where we went all the way to the chinese gardens, thru some restrictions right at the halocline depth. Difficult to negotiate your way around tight places when you cannot see anything!

The chinese garden in Taj Mahal is a wide open room, densely decorated, with very white speleothems and walls.

The fauna of these caves are a subject in itself. I confess I go most for the feeling of adventure, of swimming thru tunnels and rooms, and not so much for the animal life. It's quite the opposite in open waters, where fauna and flora are the highlights.

But I understand that the subject may be fascinating for some people. The first fact is that you don't get to see a lot. The caves are low energy places so they do not sustain much life. As you go from the lighted entrance to the penumbra to the dark recesses of the caves, life gets sparser, and the animals go from tetras (small carnivore fish that fill the open waters in significant numbers), to the white shrimps, and finally to the stygobiotic species, blind, white, no eyes, crustaceans and fish. Of these, some are reasonably rare but others you get to see in every dive.

The latter are threatened and risk extinction. Cave divers are a contributing fact. When we enter the caves with our lights on, tetras in significant numbers follow us and have a banquet on the sparse population of stygobiotic animals. You can actually see the tetras gulping them up. Even if we enter with our lights off, they have so much adapted that they follow us anyway. Sometimes you are over a thousand meters inside and they are still there. I feel like killing them. Impossible task.

This is obviously not the only impact we force upon the caves... the clearing for access generated the green algae bloom in Carwash that is so visually appealing appealing when you start your dive. Artificial lights in Dos Ojos for snorkelers, did the same. Close to major population centers, Cenotes are not really divable any longer. And the list goes on. It's a difficult line to draw.

Anyway, by the third day I was feeling somewhat more in control, and decided to make a change in diving configuration that reset all I had learned during the previous days. A drysuit.

The first thing I found is that a drysuit is a misnomer. It's only dry before immersion. Ok, not a lot of water gets in, but if one in 10 dives is totally dry, one in 10 is totally wet, and the remainder are somewhere in between. Then managing the air bubble inside the suit is a skill that must be acquired. It would be easy in open water, but in a cave with limited headroom, it becomes a little complicated. So on my first dive, I had a lot of air in my feet (the boots are way too big and I did not have any insulation on my feet) that controlling the fins was becoming a cumbersome task.

So I wrapped duct tape around my ankles after refusing to pay 120 bucks to our dear DIR friends from Zero Gravity for a pair of gaiters. They are basically a piece of elastic band with Velcro that wraps around your ankles and helps managing the amount of air that gets to the lower extremities. Not sure if duct tape is DIR or do it wrong, but it worked. I mean, sort of. I was so paranoid in not letting a lot of swooshing air into the suit that I ended up pinching myself behind the knees hard enough to park the suit in the closet for the rest of the vacation while the skin chaff heals... So 2 days of dry suit diving was all I managed.

One of the dry (ok, semi dry) dives was in the river run in Pondrosa. This is a fantastic dive. It's called the river run because the fresh water lens flows fast over the salt water. You can go upstream, below the halocline, in still water, and then return riding the river downstream a couple of meters higher up. The halocline is so clearly marked that the fresh water generates chop action when going round speleothems. The illusion of flying over a river is absolute. It's a wonderful dive, not to be missed. Nowhere else is the halocline so clearly marked.

Still plenty to come. I hope, because my ears are hurting.