While far from the most serious, out of country travel restrictions are one of the many negative impacts of the covid pandemic. The inability to travel out of country has resulted in my finally adjusting to diving in the cold waters of my home province and quickly turned me into a fan of dry suits. When I was offered the chance to join a group from Dive World Canada heading to dive the cenotes in and around Tulum, Mexico the thought of diving in warm water was too much to resist.
In non-covid times, Dive World regularly offers their clients the opportunity to travel outside of Canada. While offering courses and selling equipment provides the skills and tools, owner Mario Medarevic knows clients want to be able to travel with a group of like minded individuals. Even though we would be diving with the knowledgeable guides from ProDive International, I appreciated the confidence that came with knowing I was diving with a group of experienced instructors and divemasters.
What are Cenotes?
A cenote is a natural sinkhole where the limestone ceiling of a cave has collapsed. Pronounced “seh-no-tay”, it is derived from the Yucatec Mayan word “ts’onot” meaning “place with underground water”. Mexico has the greatest concentration of cenotes in the world with over 6000 cenotes found in the Yucatan Peninsula alone. Prior to the coming of Europeans, the Yucatan was inhabited by the Mayan people who were famed for their architecture as well as their superior astrological knowledge. Cenotes played significant role to the Mayan people because they were the only source of fresh water in the area which has neither rivers nor streams.
Cenotes come in all sorts of different shapes and sizes. The most common types of cenotes are Cave, Semi-Open and Open Cenotes. Cave cenotes being the youngest and the open cenote being the oldest as it’s cave ceiling has fallen into itself.
Individual cenotes are connected by flooded caves which continue to be explored. In 2018, cave divers found the link between Sistema Dos Ojos and Sistema Sac Actun at the time becoming the largest flooded cave system in the world at 346 kilometers (215 miles)
Cavern vs Cave diving
It is important to make the distinction between cavern and cave diving when considering diving cenotes. In cavern diving, there is a direct opening to the surface or a diver is within 60 meters or 200 feet of the direct opening to the surface. Within these parameters, a diver is able to utilize the same emergency procedures they would in open water – an independent, emergency ascent. While a cavern diver will use a guideline to navigate through the cavern, they will be able to keep the opening or light from the opening easily within sight. These measures help to keep cavern diving within the same safety parameters as an open water environment.
Cave divers go far beyond the 60 meters or 200 feet environment of cavern divers and due to the closed, overhead environment require highly specialized training and equipment to ensure diver safety. Because a cave diver would need to make their way back to a direct opening to the surface in an emergency situation, cave divers are both trained and equipped to enable self rescue should an emergency occur. They need to have instructor quality buoyancy and control to avoid creating silt storms or damaging fragile structures within the cave system.
To dive the cenotes, you need the expertise of local guides who are familiar with the conditions in each cenote. The team from ProDive International were our guides for the week. Our briefing on day one detailed the safety procedures we would use and set us up for a safe and fun week. There was a maximum of 4 divers with each guide and we each had an assigned position within our group. Each diver was required to carry a light for signaling and sightseeing. We followed the rule of thirds when it came to managing our air. One third on the way in, one third for the trip out and one third in reserve. A number of our group were also diving side mount meaning they had two independent tanks which while not a necessity when you follow the rule of thirds, provides extra reassurance.
Diving the cenotes in the Rivera Maya region you may encounter two different types of haloclines. The first is where salt and fresh water meet. Due to its greater density, salt water will sink below the fresh and where they mix it creates a blurry, hazy effect. The haloclines can be quite pronounced. In Cenote Kukulkan, we passed through a hazy section about 2 – 3 feet in depth and came out below in a perfectly clear stretch of water. Taking a breath you could rise up a few inches and be partially in and out of the hazy spot. Images 1 and 2 in the grid above are taken in the middle of the halocline in Cenote Chikin-Ha.
Cenotes El Pit and Angelita are famous for the hydrogen sulfide layers that appear at roughly 30 meters (90 feet). These cylindrical shaped cenotes are much deeper than they appear. The hydrogen sulfide layer looks like dense fog. With a mound of dirt in the centre and tree limbs poking out of the fog its easy to think that you have reached the bottom. The hydrogen sulfide layer is 10 – 15 feet in depth and once you go below it you are in very dark but clear, salt water.
I chose to wait above the halocline to try to capture picture of my dive group as they ascended up through the layer. The instructions from our guide was to “wait right here” because we would quickly lose sight of each other despite all the lighting we had with us. She was absolutely correct. Other than the light from my strobes, I couldn’t see any other light source when they dropped down below the halocline. Images 3, 4 and 5 in the grid above are of my dive group descending and coming back up out of the halocline.
Diving the cenotes is much more than simply seeing rocks. Each cenote opening was different. Some were like shallow ponds full of lilly pads, turtles and freshwater fish. Others looked like a jungle oasis perfect for an afternoon relaxing on a floaty. Some of the cenotes feature large open caverns with rock piles from centuries of cave ins. Others have twisty passages full of stalactites and stalagmites of every shape and size. Our guides planned our week so that each day was different and increased in difficulty as they became comfortable with our skills. I appreciated their approach as well as their knowledge of the features of each site.
For my next trip, I would want to bring at least one high-lumen focus light. Although I was shooting with two Ikelite DS 160’s, in some spots it was difficult to get the shot I was looking for without leveraging additional light from one of my dive buddies. Even if I wasn’t taking pictures, the extra light would not have gone to waste.
With thanks to my diver models: Mario Medarevic, Stephen Clarke, Mareesha Kulps, Daniel Negrea, Diego Giaccomo,