BY SUSAN COCKING
scocking@MiamiHerald.com
AKUMAL, MEXICO — Jumping off a 15-foot cliff into a water-filled cave aptly named ”the Pit,” I felt like I was the star of my own Indiana Jones movie. Except my wardrobe was all wrong — no jaunty bush hat for me. David Diaz and I were about to dive 140 feet deep underwater, and for that we wore wet suit, hood, mask, fins and scuba tanks and carried some really bright lights.
The Pit is one of thousands of cenotes, or sinkholes, dotting Mexico’s Yucatan Peninsula — some explored and mapped, but most covered by the region’s lush jungle canopy. Cenote is the Spanish rendering of what the Mayas call tznot, or sacred well.
Maya villages, culture, and customs were built around cenotes, which they used as a water source and regarded as windows into the underworld. Many lead to vast underground rivers flowing beneath the region’s porous limestone land surface — including the Pit, which is part of the large Dos Ojos (two eyes) underwater cave system and surveyed to a depth of 400 feet.
Diaz, a divemaster with Ruben’s Dive Shop in Tulum, and I had agreed on a dive plan: Drop down to the floor of the entrance cavern at 140 feet, explore no longer than eight minutes, then gradually begin ascending, including a five-minute safety stop at 15 feet. We would not stray any deeper inside the cave than we could see the sunlight from the surface.
CHALLENGING START
But just prepping for the dive was a challenge. We bumped down a dirt track through the jungle in Diaz’s pickup — only to encounter a boulder field in front of the entrance of the Pit. Just as I was starting to wonder how we were going to make that final 100 feet over rocks more than 10 feet in diameter, Diaz began picking his way up and over their rounded surfaces in 4-wheel drive.
”A Hummer got stuck here once,” he said with a grin.
If that was supposed to ease my mind, it didn’t.
Somehow, Diaz cleared the rocky path and parked a few feet from the Pit.
Pretending that I jump into mysterious Mexican water caves every day, I fastened my buoyancy compensator and regulator to my tank and squeezed into my Stay-Puft Marshmallow Man, five-millimeter wet suit and hood. Water temperatures usually are 77 to 79 degrees, and I wanted to avoid getting cold during a long dive. Diaz, a wiry, athletic 26-year-old, donned two three-millimeter wet suits, so I didn’t feel overdressed.
Diaz took my tank set, and I walked over to the edge of the Pit. Clutching fins and weight belt with one hand and mask with the other, I made a giant stride off the ledge and splashed down, fortunately not losing any gear. Diaz lowered my tank down on the line and I put it on. Next he lowered his tank into the water and plunged in.
Switching on our lights, we began our descent.
MIND GAMES
For the first 30 feet or so, the water was so transparent as to be utterly invisible, but then it became blurry, like looking through a camera out of focus. This is where the surface layer of freshwater meets saltwater seeping in from the ocean. Continuing down to 100 feet, we passed through what looked like a bank of wispy clouds surrounding a mountaintop. The ”cloud” is made by organic matter that falls into the pit and dissolves, forming an acid layer. The ”mountaintop” is a pile of dirt and debris not yet decomposed.
Looking at a mountaintop cloud bank while submerged 100 feet below the earth’s surface can play tricks on the mind. I was glad I eschew recreational drugs. If this is real life, who needs hallucinogens, right?
At 140 feet, Diaz shone his light on a pile of large bones. Not being an archaeologist, I had no idea what they were. He told me later they are believed to be from some prehistoric big cat. But even more impressive — at 75 feet deep — were what was clearly a human skull missing its teeth and facial bones and then, nearby, a human jawbone with most of its molars.
We continued our deliberate ascent, finally stopping at 15 feet to clear nitrogen built up from the deep dive out of our tissues. Above us, what seemed like an army of divers was jumping into the water, donning gear, readying video cameras and generally kicking up a ruckus. I was grateful Diaz and I were the first visitors to the Pit that morning.
SPECIAL PLACE
After getting out of the water, hoisting up our gear and climbing a rocky path to exit the Pit, I asked Diaz if anyone knew the age of the human bones we had seen.
He said they are estimated at 8,000 to 12,000 years old, but said no one knows for sure because none has been scientifically dated.
Sheepishly, he added that a Mexican archaeologist, diving the Pit for the first time, accidentally kicked one of the bones with an errant fin and broke it. Embarrassed, the official never got around to aging it.
Diaz, who has lived on Mexico’s Riviera Maya coast since childhood, said the Pit is one of his favorite dives. Although the entrance cavern lacks the gorgeous stalactites and stalagmites of other nearby cenotes such as the Bat Cave, Dreamgate and Mystic River, Diaz reveres this porthole into history.
”I like the bones,” he said, simply.
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