Scuba Diving The Cenotes

Approaching the water filled opening in the rock face, you couldn't help be filled with a little trepidation - afterall diving underground for the first time was a little daunting.

But for the more adventurous divers, the natural wonders of the Mexican Cenotes offer a tantalising glimpse into the hidden underwater world beneath the earth.



Hidden away among the rain forest, the honeycomb of fresh-water caves that zig-zag beneath the Yucatan peninsula were a sacred place for the Mayan people - and the magical, enigmatic and unique systems have become a mecca for cave diving enthusiasts.

In this day and age with most of the world's dive sites having been mapped, explored and photographed, it's hard to find somewhere totally unspoilt. But driving to the site of Chac Mool along a dusty track an hour earlier, it felt like being a dive pioneer.

Quick bit of history - thousands of years ago, the Yucatan peninsula was originally under the ocean. At some point it is believed the sea dropped as much as 100m and the limestone foundation of fossilized coral beds and ocean floor was open to the air. Over time rainwater seeped through the porous rock to form subterranean channels and water filled sinkholes, or Cenotes. As there are no above rivers in this area, all of the ground water sinks through the porous limestone and travels to the sea in underground rivers, gorging through the rock to create magnificent underground caves.

Dropping into the crystal clear turquoise-tinged waters following our guide Julian felt like floating in space. The only visible sign that you were underwater were the bubbles trickling from your regs. The light streaming in from the sinkhole above reflected a brilliant blue and green of the foliage above.

After dancing around the edge of the cavern for a few minutes, we pushed deeper inside the cavern until there was just three metres between the ceiling and the floor. The light from our torches cut through the darkness to reveal the beautiful decorations of fossils, and stalactites and stalagmites that had formed from the mineral deposits slowly trickling there way from above.

As we neared the mouth of the cave, for which we would not penetrate, we were treated to the amazing halocline experience. This is where fresh water and heavier salt water meet. Mixing the two created a bizarre shimmering effect that felt live my mask had been switched for one with frosted glass.

Pushing on, we emerged through back into the daylight zone and towards another cavern with an air pocket. It felt strange ascending into the darkness but we were treated to a awe-inspiring site, a cathedral like dome filled with amazing constellations of rock formations hinting at the amazing formation of the planet as we know it. Roots from the trees on the surface above had forced their way through the rock to sip at the fresh water below.

All too soon, our dives here were over, but the experiences of being underground and the majestic sites will stay with us forever. This is surely one of the most memorable dives in my log book.

video extract of our dive by Robert Moesl Underwater Productions

Best Time to Go - This part of the world is in ‘hurricane alley’ so it is best to avoid later summer when they are prone to strike. We went at the beginning of May and the weather was great.

Best Dive Sites - from what people say, any of the Cenotes will be worth diving. Some are better for beginners than others

What to See - there is little life underwater that we saw but that is not to say your eyes won’t feast on the cathedral-like sights inside. At Chac Mool there were plenty of stalactites and stalagmites and fossils of marine creatures that once filled the ocean.

The second part of the dive we hit the water at 12 noon just in time for an amazing light show. As the sun reached it's zenith, the light shot through a tiny air hole in the rock above penetrating the water with a brilliant blue laser beam.



There is an air dome on the second part of the cavern with tree trunks sticking down through the ceiling to get to the water like some giant elephant’s feet.

Viz - Brilliant the water in gin clear giving the impression that you are flying through mid air. Remember though that some parts of the cavern are in darkness so you are reliant on your torch beam. And if you hit the halocline it can feel like diving with frosted glass on your mask.

Biggest Gripe - I didn’t get to dive more of them. My own fault

What suit to take - Even though this was an overhead environment, the water temperature was an amazing 25C. I stuck with my full 3mm but some dived in a 3mm shortie.

Where to Stay - Anywhere in the Yucatan. We stayed in Cozumel so we could enjoy some brilliant reef diving with Dressel Divers. They also arranged trips to the Cenotes for us with one of their other centres on the mainland. It meant an early start and ferry ride which all adds to the adventure.

I would dive with them again and our guide Julian was extremely experienced having charted a number of new caves himself.

Miscellaneous Diving Info - By the very nature of the Cenotes, they are out in the sticks so don’t expect plush facilities (if any at all). This has the feel of real pioneer diving (even though the sites we dived and guides we went with were perfectly safe) so be prepared to kit up in the forest or dirt car park and wazz behind a tree - but be prepared to be wowed. You may have to walk through the forest so open heeled fins and wetsuit boots are a good investment.

Buoyancy is key to a good dive so make sure you are properly weighted.

Also it can be dark down there. The furthest you are from the surface is 60m (the combined depth and distance penetration into the cavern) but this is an overhead environment so make sure you are prepared mentally for that otherwise it could be an uncomfortable time for you. Also the halocline can be a little unnerving.

Guidebook - Underwater Editions Cenotes dive guide and logbook offers a comprehensive insight into diving the Cenotes as well as some brilliant maps. It’s out of stock at the moment but keep checking the link, it’s an invaluable resource.

Worth Going - hell yes!

Green Force Torch

Below is my review of the Green Force AA12 trorch with Tristar Plus LED Dimmable head that I first posted on the Dive Magazine website in a bid to win a canvas Great White Shark print taken by Maria Munn of ocean Visions.
Apologies for the length but I've chucked everything in for you.



WITH LIGHTSABER LOOKS THEY'LL BE NO DARK SIDE UNDER WATER

Strengths:As tough as Chuck Norris, ruggedly stylish as Steve McQueen, flexible as Olga Korbett and as bright as the nerdy kid at school who always put their hand up when the teacher asked a question

Weaknesses:Not cheap. Clumsy divers risk flood it when switching it off and the different brightness settings require the reflexes of…someone with very good reflexes.

Writing a review on a dive torch always seemed somewhat pointless to me. You get into the water, turn it on and point the shiny end at the thing you want to see. If the lamp is any good said thing will exude a wonderful spectrum of colour. Simple. Straightforward. Job done.

But that was before I agonised for two months over whether to part with more than £350 notes for the Belgium-made Green Force AA12 Tristar Plus and struggled to find a truly warts-and-all independent perspective.

So what do you get for your money?Green Force torches are the Land Rover of dive lights, expensive but ruggedly stylish. The company’s selling point is that the system is completely modular. You buy a battery pack and marry it up with a light head of your choice, be it halogen, LED or HID. Then simply interchange and upgrade parts as you wish, or turn it from a hand torch to a cylinder-mounted umbilical, without having to splash out on the basics again.

My mid-priced pack came with an AA12 battery, Tristar Plus dimmable LED head, mains charger, charging pin, carry cases and towel, a package vastly cheaper than the sum of its parts.The unit works by screwing the head fully into the battery (or umbilical) until the connections meet.

Three O-rings provide protection from flooding and a half twist either way is enough to switch the light on or off. But here is my first quibble. While you have no switches to worry about leaking, a lot of hard-earned cash is being entrusted to three O-rings, and a diver’s grasp of half-a-turn. I fear some could flood their unit if not careful, or narked (yes, it happens to us all) by unscrewing it too far at depth. To avoid that I switched mine on just before hitting the water and left it on.The three o-rings require regular checks and battery is a bit high-maintenance. But that should keep many divers like me happy on the wet weekday nights when we long to be in the water.

Once assembled, the black-ridged battery cylinder and the greeny-gold aluminium light head resembled an underwater lightsaber (ok, I’m a child of the 70s) and I hit the water like some diving Jedi. Rather than buy the handle, I fixed a split ring and dog-clip to a hole in the battery casing (designed for the handle fixing) and hung it from a D-ring on the shoulder of my BCD. That allowed me to hold the torch comfortably without having to extend my arm in front of me and gave me peace of mind knowing that, should I let go, it would dangle from my jacket rather than vanish to the depths.

The Tristar Plus has three bright and unbreakable LEDs which deliver 30 watts but require very little power, giving 150 minutes of burn time with the AA12 battery. I easily got two 60 minute dives out of mine with no problems. but if that’s not enough, fit the head to the Flexi IV battery and get 960 minutes burn time. Oh, the beauty of a modular system.

The colour temperature of the LEDs is closer to natural daylight than halogen bulbs and helps replace colours normally lost to the blue (not as well as the costly HID heads do but I can always upgrade later). The 20-degree beam also produces a nice cool and evenly diffused light.

Diving the James Eagan Layne on a particularly bad day, it certainly helped slice through the murk and on a night dive, it illuminated so much reef I thought the sun had come up early. I didn't miss much on that dive. The dimmable LED head has three brightness settings, a strobe and an SOS.

And here is my second quibble. To switch between them you first have to turn the light on, then turn it off after less than five seconds, and then back on again. To go from maximum brightness to SOS you have to repeat the process four times. A bit of a fiddle and a faff and, 20m down, we all know five seconds becomes 15 in no time. It is a feature I can see few divers making full use of.

So, if after reading 750 odd words on a tube with a shiny end you're still asking if you should buy one, my answer is an unequivocal ‘Yes. For the Force is strong in this one.’