I was first introduced to cave diving in 1994 when Frans Vandermolen invited me to join his expedition team to explore Bower Cave, in Yosemite California. During the 1870's, this cave was a popular tourist attraction for travelers who had arrived on horseback and in buggies. A stage had been constructed for the regular shindigs and is still present today, high on the caverns wall. After repelling ourselves and gear 100' into the large cavern, we re-energized ourselves with food and water before gearing up for the first dive. The water in the spring was in the 40's and had the second highest e-coli count reported in the entire Sierra mountain chain.

I buddied up with my friend and mentor, Bob Titus. Once beyond the cavern zone, the visibility inside the cave opened up like pure Sparklets Water. Within no time we found ourselves deep inside the cave. The depth required a greater volumes of gas than we were carrying, giving us no choice but to turn the dive only after about 30 minutes. The whole project required a lot of work, but fun non the less.

bower cave stageBower Cave

Bower cave is currently managed by the USDA Forest Service and is not accessible to the general public. With any luck, we will be able to re-explore the cave and provide further data and a extensive map of this aquifer for the general public and research agencies. Until then, there are several other places to explore.

Ancient Mayan city of Tulum

The following year, Frans drug my butt down to the Yucatan and I completed a full cave diving course. I was hooked. Beside the bugs and militants in the jungle, this was the most exciting dive trip I had ever been on. I continued to return to the Yucatan, and taught cavern diving courses to several organized groups. During one of these trips an opportunity arose to do some exploration with local cave explorer, Bil Phillips. This ended in the mapping of the Lithium Sunset area of a cave called, Sistema Sac Aktun. Today, this cave is one of the longest underwater caves in the world with nearly 30 miles of mapped passages. It is still under exploration and survey by the Quintana Roo Speleological Society and there is no telling where it will end.

John in the Chan Ho cave entrance
Preparing to squeeze through the "Chan Ho" cave entrance

Each time I return to the Yucatan I learned a little more about the vast history that we have been venturing thru. Much to the thanks of friends like Bil Philips. Canadian born, Bil has resided in the Yucatan's cave country for over a decade. He loves to share his wealth of information about the land, people and the caves that he has interacted with over the years. Currently, Bil lives in Tulum, Mexico and has a fantastic dive operation called, Speleotech" that provides education, guide services, equipment rental and lodging for diver from all continents.

speleotechBil Phillips Naranjal

Many scientist believe that a large meteor hit the Yucatan Peninsula approximently 65 million years ago. They refer to this as the "KT event". This event is thought to have caused the demise of most of earths species, including the dinosaurs. At that time, the Yucatan Peninsula was completely submerged underwater. It had thriving marine reefs, rich with coral, shellfish and other marine organisms. Millions of years of dead coral and shellfish had been building upon each other. The created a deep bed of calcium rich material.

KT eventdead dino
It is estimated that this meteor had a 5 mile circumference and left an imprint in the earth 112 miles in diameter. The impact site can still be seen in the Puerto Chicxulub area of Mexico's Yucatan Peninsula. When this meteor struck, the earth rippled for hundreds of mile around, churning water and earth.

Over the next 65 million years, the planet's sea level had dropped then risen many times. Today it is suspected that the sea level is approximently 200' lower than when the KT meteor struck. Much of the calcium from the ancient marine reefs in the area had been transformed into limestone. At the later part of our last ice age, known as the Wisconsin Glaciation, rivers of water flowed over the earth as the ice shelfs melted. This water combined with nitrogen and carbon dioxide in the air, creating weak acid's which slowly dissolved some of the limestone. This dissolution formed a plethora of tunnels in the earth that we now call caves. And in them we can sometimes see the shells of ancient marine invertebrates that never decomposed.

Early man and animals inhabited these caves, probably for protection from the climate and any predators out to kill them. During this period water continued to flow over and through many of these caves as air flowed through them from remote entrances. Precipitation from the soil above drew more calcium into the cave. Much of this calcium solidified when it was exposed to the air. This process created beautiful cave decorations known as "speleothems".

10,500 year old human skeleton
Photo by Bill Reals of a 10,500 year old human skeleton in a underwater cave in the Yucatan. Note that the legs appear to have been crossed. It is thought that people of this period were sat upright with there legs crossed when they were put to rest.


prehistoric megatherium sloth skeleton
Photo by Bill Reals of John Walker inspecting the remains of a prehistoric ground sloth (Mylodon) which inhabited these caves when they were dry. This animal was a herbivore and could have grown to be as large as 500lb. (227kg)


John in Decorated Underwater Cave
Photo by Bill Reals showing what the solidified calcium looks like. Speleothems have many other sub-names. Stalactite, stalagmites, helictite, rimstone, flowstone, bacon, just to name a few. They can be fragile and contact should be avoided to preserve these for years to come.


 Freindly Mayan indians

Mayan Indians have inhabited this area for many years. Researchers believe that the nearby stone town of Tulum was built around AD 560. The Maya believed that gods lived in the water filled holes in the ground. They named these holes D'zonot. When the Spanish arrived in the 1500's to concur the peninsula, the name Cenote was derived from the Yucatec Maya word D'zonot. Sacrificial offerings were given to these gods in hopes that they could prosper. The Maya were very amazing astronomers and the first to come up with a complete calendar and written numbering system.

Sadly, Spanish Conquistadors, disease and drought devastated many of the Maya. Today few Maya families still reside in and around the Yucatan jungle. Many of these families had been given land under the Ejido System, providing them with a natural resource for agriculture and hunting. During these cave diving excursion we often meet these generous people and kick down a few pesos so we can enter the cenotes on their land. Those of them who speak Spanish often refer to us as loco gringos underground.

Ancient city of Tulum 546 ad
Photo by Scott Brooks: Inside the ancient walled city of Tulum.

Tulum is one of the few ancient Mayan cities located along the Caribbean Coast. It is thought to have served as a trading port which converged routes from both land and sea. It is now a beautiful and intriguing tourist destination.


Mayan Pottery in Yucatan Cave
Photo by Bill Reals : These vase that were found in an underwater cave just south of Tulum by Robby Schmittner. Although they "could" have been used for sacrificial offerings, there actual age and purpose it not quit clear.


Disclaimer:
This site is NOT intended to teach anyone how they should dive. It is simply reflecting on what I have done and continue to do and is my opinion only. Proper dive training should be gained before attempting anything involving the use of a Self Contained Underwater Breathing Apparatus (SCUBA).