Arnotify

Rob, a friend from work, had been recommending me to dive in the Yucatan area for a while, and in particular to dive a cenote. I finally got to follow his advice and dive my first cenote today, and what an experience it was.

A cenote, or d’zenot (sacred well) in Maya, is a collapsed cavern part of an underground system of caves, caverns and rivers flowing to the sea, carved over centuries by the rainwater penetrating the limestone. At the surface they appear as large sink-holes in the middle of the jungle but they are doorways to a fantastic underwater world.

I dived the cenote Chac Mool (the claw of the Jaguar), located south of Playa del Carmen.

The water in the cenotes is clear as air, offering visibility of over 70m. The Chac Mool cavern featured stalagtite and stalagmite, proof that it was dry at some point. Indeed, during the last Ice Age, some 12,000 years ago, the water level of the world’s ocean was some 100m lower.

Some of the stalagtites and stalagmites are slanted at steep angles which is another sign of the violent geologic event that shaped the region. Sixty-five million years ago an asteroid 10 to 20 km wide collided nearby at the present day location of the Chicxulub village, pushing 70% of Earth’s species, including the dinosaurs, into extinction. Some fossils were also visible, embedded in the limestone.

In contrast to the signs of these dramatic events, the shafts of light peering from the surface evoked the peacefulness of a cathedral. When crossing the halocline, the boundary between fresh and salt water, at about 10m of depth, the light is distorted at it passes through the water, enshrounding you in a dream-like haze.

It was a fantastic experience and incidentally my 100th logged dive. What a way to celebrate. Thanks Rob.

Some people really should not dive.

After your initial dive training, you get a certification card, or C-card. Mind you, unlike a driver license, once you have a C-card it never expires and cannot be revoked. Unfortunately, maybe.

This makes some sense, though: at the wheel of a car you could hurt many more people than yourself. With diving, if you do something stupid, you´re the one most likely to suffer the consequences.

This afternoon’s dive offered several examples of what not to do as a diver, from the minor to the frightful.

During the dive briefing, the divemaster is always very clear about what you´re supposed to do and not to do. This time, as always, Miguel reminded everyone to follow him and stay behind him.

All the dive sites over the Cozumel reef are drift dives. That’s the easiest and most relaxing way to dive: you just let the current carry you along. You don´t even have to kick your fins. You can just sit back and enjoy the ride, literally.

Now, if you start kicking, you´re going to go fast. You´re going to go much faster than everybody else and you will end up separated from your group. That´s what happened to four of the divers. They went way past the lead divemaster into the blue yonder. Miguel, our divemaster, started banging his tank to get their attention and gestured for them to come back and rejoin the group. Did they? No, of course not. One of them, once they were back on the boat, even complained that the divemaster was banging on his tank. Well, duh.

That was funfest number one. Now, Cozumel is a national marine park. To preserve the fragile reef ecosystem, you should not touch any sponge or coral. You could accidentally break it. But the natural oil on your skin also degrades the protective coating that protects those fragile organisms from bacteria. The divemaster also reminds you of this during the dive briefing.

But one of the divers in our group was a grabber. Accidents happen and sometimes you brush against a sponge. But this guy was just grabbing and holding on to sponges. Repeatedly. He also grabbed some of shrimp and started playing with it. Argg… Why on earth would you do that?

I must say in general that divers are quite well behaved. After all, if they want to keep enjoying diving, it is in their interest to preserve the reefs. But there always has to be an exception.

And now for another behavior that could land someone a Darwin award. It was actually a combined effort. One of them was a diver with our group (one of those that kept getting separated) and the other was a young snorkeler, a friend of the diver.

The snorkeler was tagging along with us and from time to time would freedive. At one point, as the snorkeler was freediving, the diver gave him his spare second stage and the snorkeler took a breath.

Now, and it apparently wasn´t obvious to either one of them, but this is a really bad idea. He took a breath of compressed air, then zoomed back to the surface. When you do that, the air in your lungs expand because of the difference in pressure between the depth and the surface (Boyle´s law). As a result you can end up with more air than your lungs have the capacity to hold. This can create all sort of interesting things, including arterial gas embolism (the lung´s alevoli are distended, then rupture, then gas leaks into the arterial), mediastinal/subcutaneous emphysema (the lung tears and air leaks into the cavity between the two lungs) or pneumothorax (collapsed lung).

When he saw this Miguel started gesturing big no-no signs. Once we were back on the surface he told the diver not to repeat that performance, and she was acting somewhat bothered, wondering what she had done wrong. Now, when you don’t really know what you’re doing and someone tells you “what you just did was very dangerous”, please, believe them. Don´t just argue with them and say “well, nothing happened”. The point is that something could have happened.

Each diver is responsible for their own actions. A divemaster is only there as a guide and advisor. Whether you decide to follow their recommendation or not is your call. After all, it´s your life.

I have completed my training as a Divemaster. I have passed all the theory exams, the swim tests and the practical application part of the training. I’ll need to mail in some paperwork, pay my annual dues and liability insurance and I’ll receive my authentic Divemaster card!

This was different than the Rescue Diver training I took a couple of years ago. Rescue Diver is very physical. You have many rescue exercises to do, some of which are quite demanding. For Divemaster, you have to learn a lot of theory (physics, physiology, decompression theory) as well as how to interact with student divers and instructors. However, it´s not physically quite as demanding. I´m glad to have completed both training now. Next step would be the Dive Instructor certification, but I think I´ll wait to get a bit more experience to go for it, although Gabriel tells me it´s essentially focused on marketing.

Three more dives yesterday, and another three today, including a night dive. Nigth diving is really a special experience.

There are at least four different things interesting about diving: the equipment, the fauna, the landscape, the physical experience.

For some people, diving is a great excuse to buy piles of gadget and expensive and complex equipment: compressed air cylinders, exotic gases (argon, helium, nitrox), underwater lights and cameras, etc… You dive because you have to test the equipment. Others couldn´t care less about the equipment: if they could swallow a pill and breathe underwater without equipment, they would.

For some people it´s all about the fauna and flora. They know all about the mating habits of the mantis shrimp and can distinguish between the juvenile, male and female parrot fish. When they’re in the water, they look in crevices and under overhangs for the rarest species. They often have cameras, but not for the equipment, but as a way to record their finds.

Some dive sites, especially deep ones, don’t have much animal life. Instead, there’s the beauty of the reef to enjoy, the towering coral heads, the butresses, the swim throughs, the huge barrel sponges, the fantastic underwater landscapes that feel as if they were from another planet.

And then, there´s the experience of being free from gravity. You don´t weigh anything anymore. You can move left, right, forward, back or up and down. You can move just as easily upright, horizontal, on your side or upside down for that matter. Moving is effortless. You barely have to think “up” and your breathing pattern changes, affecting your buyoancy and causing you to rise. Or a quick flick of your fins and you are propulsed forward.

I´m not much into the equipment, and although the landscapes and the animals are fascinating, I like the physical experience the best. At night, this experience is intensified. You can turn off your light, look away from the other divers and you find yourself floating in space, with nothing around you but the sparkle of the photoluminescent plankton as you wave your hand in front of you and the sound of the bubbles as you exhale. For a moment you feel like Dave Bowman in 2001: A Space Odyssey.

Actually, I think I´m getting a sense for what astronauts feel like when they travel back to earth. Yesterday I was lying in bed reading, and I wanted to roll. I pushed against the headstand, and I was surprised and disapointed to realize that my body would not just float away as I had been expecting, and as it would have underwater. Instead I had to prop myself up, then clumsily move around. Unfortunately, sometimes you have to get out of the water, just like sometimes you have to get back to earth.

Today I went on the so-called “fast-boat”. It’s not really that much faster as we leave at 8am, half-an-hour before the regular boat, and return only an hour earlier. It is however taking a maximum of eight divers and a single divemaster, and therefore less crowded.

We went to Santa Rosa Wall, then Tormentos Reef. Both dives were great, with less eratic currents than yesterday. Our Divemaster was an expert naturalist, particularly good at picking out the small things in the sand: a couple of Jackknife fish (black and white stripes and a long dorsal fin) hiding in the coral reef, crab, spider shrimp, tiny flounders and larger ones. We also saw the usual baracudas and giant groupers and a very friendly large angelfish who was probably expecting some food from us. I also heard the dolphins again, but didn’t see them this time.

It was the first day of diving in a year for one of the divers on the boat, John. As he was setting up his equipment, his regulator started freeflowing (that is, it started delivering air continuously and forcefully making quite a loud noise). It happens sometimes when the diaphragm of the regulator gets stuck. John started fumbling with it, hitting it and shaking it violently with no effect. I grabbed it from him and put two fingers in front of the air out-take, unsticking the diaphragm and stopping the freeflow. John thanked me and added “I was just checking if it was still working. Haven´t used it in a year”. OK. Well, scuba diving equipment is life support equipment. Specifically, your life. It needs an annual maintenance check, because when you´re about to go on a dive is not the time to find that you should have maintained it. I could tell already that this guy was going to be fun, so I signed up to be his buddy (I need the practice to handle emergencies). Indeed, once we were in the water John had various problems. He wasn´t weighted properly and didn´t have good buoyancy control, so he kept floating up. At one point he started floating toward the surface out of control, which can be dangerous as this can cause decompression sickness or lung overexpansion injury, so I went after him, took control of his BCD and emptied all his air so he could go back down. It´s at this point I found out that his dive computer´s battery had run out, so he had no depth gauge nor a check on his dive profile (another no-no, and another reason why you´re supposed to have yearly maintenance on your equipment). Not long after he ran out of air and I had to escort him to the surface. He started ascending way too fast, and I motionned him to slow down but let him go as my computer was beeping requesting me to slow my ascent. First rule of the Divemaster: don´t put yourself in jeopardy because someone else is doing something stupid. I eventually caught up with him, stabilized him and did our safety stop together. My respect for Divemasters increase everyday now that I start seeing through their eyes.

I went to visit San Gervasio, a site of mayan ruins in the center of the island. Since around 100BC and as late as the 16th century, women from the Yucatan were expected to make a pilgrimage to the temple of Ixchel in San Gervasio at least once in their lifetime. Ixchel in the mayan pantheon was the goddess of midwifery, fertility, medicine and weaving. Iguanas now meander amongst several buildings, temples and roads that remain in the middle of the thick jungle. I spent most of my time running from mosquitoes, but several of them managed to bite me on my feet. As it turns out, malaria is endemic in Cozumel… Oh well.

 

Tonight a US Navy ship has moored in Cozumel, and it´s shore leave for the marines, along with the usual batallion of tourists from the cruise ships (five cruise ships stationned today). Although the marines are dressed in civilian clothes, they stick out. For one thing, there are very few drunk divers in Cozumel — alcohool and diving don´t mix, “Dont´t drink and dive” as the saying goes. For another, tourists are rarely travelling in band of four or five cropped hair young guys. A pack of them got a room next to mine. I hope they´ll be reasonably quiet and I´ll be able to sleep tonight. I have some diving to do tomorrow…