chapter 8



Sobbing with grief, the woman realized her worst nightmare. Her devoted husband and 22 year old son had just drowned in the cavern at the Cenote Cristal. It was horrible end to what started as a glorious sunny afternoon the day before Christmas in 1996. The family traveled to this ecological park to swim, eat and celebrate a day together. The woman’s husband and eldest son were both certified open water divers and had brought their scuba equipment to use in the cenote basin. Discovering that the cenote was very shallow the pair decided to venture into the cave entrance not realizing the extreme danger that lied ahead. With no training in an overhead environment, no guideline to navigate their way out, no understanding of managing their air supply and only one battery light apiece, this true story is a typical story that has unfolded hundreds of times during the past thirty-five years.

Reviewing some of the most tragic accidents can help prevent future ones. Five classic rules have evolved since the 1970's. Perhaps the most credit goes to Sheck Exley who authored a very popular book in 1977 called "BASIC CAVE DIVING” - A Blueprint To Survival", published by the National Speleological Society - Cave Diving Section. This simple text took various drowning accidents involving open water divers, open water Instructors and cave divers during the late 1960's and early 1970's and described the facts of each particular accident under pseudo first names. With each accident outlined, Exley reviewed the reasons "why" the accident occurred and what measures might have prevented it. The book is still available through the NSS-CDS and is highly recommended as an important educational tool.

Since 1948, accident reports have been kept and maintained through the NSS, the NSS-CDS and the NACD. Drowning accidents and incidents in the overhead environment that have taken place in the United States, Bahamas, Mexico, Canada and the Caribbean are all on file. The majority of the 375 have occurred in Florida during the late 1960's, 1970's, and early 1980's. The worst
year was 1974 with seventeen separate drowning accidents resulting in 24 deaths The three worst accidents involving multiple numbers of divers at one time were:

Jenny Springs (now Ginnie Springs) - 4 open water divers - 1968.

Royal Springs, Suwannee County - 3 open water divers - 1980.

Vortex Springs, Holmes County - 2 open water divers and 2
Open Water Instructors - 1981.

Surprisingly, at least twenty-five open water Instructors are part of these statistics. The worst accident in Mexico's Yucatan peninsula took place on August 17th, 1995 involving three open water divers (two tourists, and a dive store owner from Cozumel) at the Cenote Calavera (Cenote Esqueleto) located
near Tulum, Quintana Roo, Mexico.

From all these accidents, at least one of three glaring factors clearly shows why these deaths occurred.

They are:

1. A continuous guideline was not used from outside the cave.

2. 2/3'rds of their air supply was not reserved to exit the cave

3. Diving too deep for the level of training and experience.

Judging from all the accident information, there was an obvious lack of cavern or cave diving training among the victims who ventured into the overhead environment. For those few accidents involving trained cavern or cave divers, the deaths were attributed to violations of established rules of safety, or their
choosing to ignore them.

Besides the three rules (guideline, air management and depth) other factors weigh in that have frequently contributed to accidents. One major factor was the number of lights used and how long they would work. Other factors were:

1. Use of alcohol and/or drugs prior to the dive.

2. Lack of proper equipment being used such as octopus,
power inflator for the BCD, or pressure gauge.

The most glaring factor was the lack of training. Reviewing the information of every accident presented, a distinct pattern emerged not having the appropriate amount of training for the particular type of dive. If a diver is trained, properly prepared, and knows his or her limitations, the odds of an accident drop. Although there is no guarantee that training will prevent you from drowning in an
underwater cave, the fact remains that "training" does make a big difference. From these statistics and information, the "Rules of Accident Analysis" was developed through the National Speleological Society - Cave Diving Section and the cave diving community. The basic five rules offered are:

1. TRAINING. Before pursuing cavern or cave diving, please
seek proper training and know your limitations.

2. GUIDELINE. Always use a single continuous guideline from
outside the cave and throughout the cavern or cave system.

3. AIR/GAS. Always use at least 2/3'rds of your beginning
air/gas supply to EXIT the cavern or cave.

4. DEPTH. Do NOT dive DEEPER than the limits of your
training and experience.

5. LIGHTS. Always use a minimum of THREE LIGHTS per
diver. For cavern diving, the sun and at least
two battery powered lights.

Human error and/or poor judgment is blamed on every cave/cavern dive accident with the exception of only one incident that involved a geological event on November 17th, 1991 at Indian Springs, Wakulla County, Florida. Following these basic FIVE RULES has established a precedent for all divers to use
and has proven, statistically, that they work for those who choose to obey them. There is no better way to communicate and emphasize SAFETY while diving caverns and caves than by being familiar with them and staying within their limits. Believe in them, practice them and share them with other divers who wish to venture and witness the beauty of the beautiful caverns and caves.


The State of Florida in the United States has certainly experienced the highest majority of drowning accidents in caverns and caves located throughout North and Central America and the Caribbean. The convenience, easy accessibility and clear water (during normal weather conditions) are perfect ingredients to attract divers of every experience level and training. Unfortunately, open water divers with no formal training in cavern and cave diving, are the majority and at the greatest risk. Trained cave divers are not immune to accidents in caves as statistics have shown.

The Riviera Maya along Mexico's beautiful Caribbean coast in the Yucatan peninsula has evolved into one of the world's largest tourist areas drawing people from all over the world. The rich history of the Mayan culture, the lush tropical environment of the Caribbean Sea and reefs, the beaches and the thick jungle are all reasons for the areas growth. Scuba diving plays an important role.

The reefs along the Maya Riviera and the Island of Cozumel which is internationally known as a major and very popular dive destination attract scores of divers. The abundance of cenotes offer consistent crystal clear water, easy accessibility, and incredible, beautiful speleothem decorations. The
Mayan Riviera has become a mirror image of the State of Florida and its past. Unfortunately, the right ingredients exist for many accidents to occur.

The following information is a review of drowning accidents that have taken place in cenotes or the “overhead environment" in the State of Quintana Roo, Mexico. This information was obtained through the NACD JOURNAL, the NSS-CDS UNDERWATER SPELEOLOGY, local police reports, and personal knowledge and experience.

Date: MARCH 15th, 1987.

Location: Cueva de Amour, located in the lagoon behind the Cancun hotel zone.

Victim: The male victim was a tourist open water diver from the United States in his early twenties.

He entered the cave without proper training, no guideline, no understanding of air management and only one light. He could not find his way out and ran out of air. His body was recovered three days later by two cave divers who were asked to fly down from Florida to perform the recovery.

Information obtained by local divers on the scene.

Date: MAY 5th, 1987.

Location: Caleta Chacalal.

Victims: 28 year old male and a 10 year old boy.

It was a beautiful Sunday afternoon; the older victim’s family was spending the weekend at his vacation home located on the Caribbean beach adjacent to the caleta. The adult was playing with his own and local children in the shallow spring basin of the caleta showing them how to breathe on a scuba regulator and tank. The adult had a Diver’s Propulsion Vehicle (DPV) and was giving some of the children rides on his back around the caleta. The adults were shooting video of the children. It was the last child’s turn to ride with the adult on the DPV (the child had his own scuba tank, regulator and buoyancy device). The victims entered the spring entrance of the caleta and made one pass around the cavern room with the brother-in-law filming. Moving further back into the cavern zone the prop of the DPV machine blasted a huge debris cone of silt (the saltwater breaks down the limestone into very fine clay silt - the most dangerous kind) and created a solid curtain between them and the exit of the cavern blocking any view of sunlight. The only lights the adult and child had were the light on the DPV and a small light attached to the child’s diving mask. In total fear, the victims followed the clear water.

The brother-in-law saw a huge cloud of silt billowing from further in the cavern and quickly swam out. Anxiously waiting outside for twenty minutes hoping the adult and child will find their way out; he realized there was a major problem. He got out of the caleta and rushed in a car south to Akumal to
seek help. He found two cave divers and they rushed back to Chacalal with their cave diving equipment within the hour. Entering the cave, they went as far as they could with their guideline and reel with no success in finding the two missing people. In despair, they ended the search. The next day two cave diving Instructors from Akumal were asked to continue the search. More family members and associates arrived throughout the day, all hoping for a miracle that the adult and child may have found an air pocket (because of the very shallow depths of the underwater cave) and may still be alive. The cave diving team searched all day, drawing a detailed map of every passage and room found with no success. No one understood why the two people could not be found so the hope of them being alive continued. In frustration, the adult’s family asked for more help. A call is placed to Florida and three more cave divers were flown down by private jet late Monday night.

They arrived at the Caleta Tuesday morning at 2:30 A.M. and begin the first dive. The victim’s were found 400 feet back. Recovery divers had to go through two tight restrictions and a very small passage to reach them.

Date: SEPTEMBER, 1988.

Location: Caleta Chacalal.

Victim: 26 year old male.

Two brothers from Peru were trying to start a diving business in Playa Del Carmen. They had heard a “rumor” of diving equipment left in the cave from the accident that took place at the Caleta Chacalal in May, 1987. Hoping to acquire more rental equipment for their inventory they decided they
would visit this Caleta, enter the cave system with a guideline and reel and search for the missing diving equipment. Neither brother was trained for cavern or cave diving or possessed the proper equipment to performed safe dive. The first brother entered the spring without a reel and guideline leading his brother
who tied off a guideline from outside. The cave soon became small and because of silt and percolation (virgin saltwater passageways ferociously percolate particles from the ceiling) the visibility quickly dropped to zero. The second brother with the reel and guideline became very stressed because of the “no” visibility and exited the cave taking with him the guideline and reel. The first brother was now trapped in the underwater cave in zero visibility without a guideline to find his way out. He quickly depleted his air supply in his single tank and drowned. Body recovery was performed by a cave diving Instructor from Akumal.

Any and all guidelines were removed from the cave. There was NO missing equipment in the caleta from the first tragedy. The surviving brother had his dead brother cremated and took him back home to Peru.

Date: OCTOBER 17th, 1990.

Location: Sistema Sac Aktun - Cenote Ho-Tul.

Victim: 38 year old male certified full-cave diver who was trained in north-central Florida with 53 logged cave dives.

This accident involved a group of eight cave divers divided in two teams. Five of the eight had just completed their full cave training the day before. All five had received their cavern and Introduction to Cave training in Florida. The group’s dive plan involved entering the cave system at Cenote Ho-Tul. (In 1990, that was the only way to enter the cave system.) The plan was to do two cave dives with two teams of four. The first dive was to traverse from Cenote Ho Tul to the Grand Cenote and return. This traverse involved a 70 foot/21 meter
jump 300 feet from Cenote Ho-Tul. (It is now one continuous guideline) The group was shown the rugged path and where to enter the water. Back at the vehicle the cave system was sketched in detail on paper explaining the cave configuration, the jump and distance. The second dive was to recalculate third’s, go a new direction and swim a small circuit called the Cuzan Nah which included a third cenote. This loop is well known for its beauty and numerous speleothem decorations. This proposed circuit dive asked for the two teams of four to go in opposite directions because of the size of the cave passages and several minor restrictions along the way. The plan had the two teams pass each other and included one jump along its path. Furthest distance from air was no more than 500 feet/151 meters. This was reviewed twice and everyone agreed they understood the proposed plan. This was the first time in this cave system
for everyone except the group leader who was very familiar with the cave.

Once in the water at the Cenote Ho-Tul everyone paired up into teams, performed their bubble check, matching and safety drill. The dive plan was reviewed again for a third time and drawn on a slate for everyone to see once again exactly what to expect. An order was established and the first dive began. It should be noted that (using pseudo first names) Gus was bringing with him a video camera. Swimming 300 feet the teams arrived at the jump clearly marked by a pink arrow marker. The group leader - Stan - attached a jump reel and turn 90 degrees installing the temporary line the 70 feet/21 meters with everyone following. Two members of the group, Tom and Fred, were helping Gus with his video camera by holding video lights as the group traversed to the Grand Cenote. Arriving at the Grand Cenote another reel was used from the permanent guideline to lead everyone out into a huge cavern zone in order to make it easier to find the permanent guideline on the return swim back to Cenote Ho-Tul. At the surface, everyone was in awe of the beauty. The dive took 24 minutes with a maximum depth of 40 feet/12 meters. Everyone had between 2300 - 2400 psi/ 156 - 163 bar in their double 80 cubic foot/10 liters tanks. Tom had 2600 psi/176 bar. All divers began the dive with 3000 psi./204 bar.

During the 15 minute surface interval, the dive plan was reviewed for the fourth time as Jeff had questioned the plan. Reviewing the sketch on the slate the dive plan was discussed for the fifth time. It was noted how much air was used making the traverse and it would probably take the same amount, if not less, to return to the Cenote Ho-Tul. One change was made with the dive plan. Instead of surfacing at the Cenote Ho-Tul, it was agreed to stay in the cavern zone, re-calculate third’s and then proceed with the loop dive of the Cuzan Nah. Dropping down at the Grand Cenote, the two teams swam over to one side of the cavern zone to observe a crocodile skeleton (no longer there as it has been removed). The first team consisted of Stan, Ann, Carl and Dan. The second team was Tom, Gus, Fred and Joe. It was agreed that the second team would pick up the two reels installed. On the return swim the first team arrived at the jump reel with the Stan detaching the gap reel and signaling his other three team members to swim ahead following the jump reel to the pink arrow marker pointing back to the Cenote Ho-Tul. Stan waited for the second team to arrive which was moments later. Three members of the second team began the swim across and Stan handed the jump reel to Tom who was the more experienced of the 2nd team with over 100 logged cave dives. Stan motioned for Tom to go ahead and reel up the jump line and then quickly proceeded to catch up with members of the first team who had now arrived at the pink arrow marker. Turning left, the first team swam for Cenote Ho-Tul with Stan now back in the lead. Stan looked over his shoulder and saw Tom reeling up the jump line and Gus beginning to follow team #1 towards Cenote Ho-Tul with Dan and Fred close to the pink arrow marker watching Tom.

The first team arrived at Cenote Ho-Tul and then realized the second team was not behind them. The group leader thought the second team must have been delayed, perhaps a jammed reel. Waiting a few minutes, the first team decided to continue the dive towards the Cuzan Nah, recalculate thirds and proceed on. Swimming 150 feet with still no sign of the second team catching up, Stan became uncomfortable and took the first team to the surface of the third cenote as too much time had gone by with “no sign” of the second team. At the surface, the first team agreed that they saw the second team at the pink arrow marker.

Stan asked the first team to stay at the third cenote, and he went back looking for the second team. He surfaced at the Cenote Ho-Tul to check in case they went there while the first team was at the third cenote, then continues on. Arriving at the pink arrow marker, to Stan’s shock he found the jump reel and guideline had been put back in place. It is believed Tom thought the first have been confused and did the “smart thing” and swam back to the Grand Cenote as it was the known exit. Just to be sure, Stan swam upstream the main line into the huge passage known as the “Paso De Lagarta” looking for any evidence of a silt trail. Seeing none, Stan concluded they did go back to the Grand Cenote. Swimming fast and hard to the Grand Cenote, he discovered the second team was not there. The question of here the second team had gone was now clearly answered in his mind. The second team did swim upstream the “Paso De Lagarta” passage. With 1500psi/100 bar remaining in Stan’s tanks and 30 minutes gone, there was no way he could “catch up” with the second team. He assumed they would figure out their mistake, call the dive and return to the
Cenote Ho-Tul since they had a continuous guideline to the surface.

Stan swam back to the third cenote to get the first team of Ann, Carl and Dan, called the dive over and returned back to Cenote Ho-Tul. Once back at the surface at Cenote Ho-Tul with team #1, Stan was down to 700 psi/47 bar and over 75 minutes had passed since the missing team was last seen. Because of
he shallow cave system, long bottom times were expected but it was approaching the time the second team would be overdue. Stan decided to go back down and look a little bit more. Having swum 80 feet/24 meters towards the pink arrow marker he immediately saw three lights of the second team 100 feet/30 meters away swimming towards him and Cenote Ho-Tul. As Stan got closer to the second team swimming towards him he saw the first two divers sharing air. One was Tom and the other he thought was Fred. Tom, seeing Stan signaled big trouble further back. Stan swam another 50 feet/15 meters and discovered a set of legs dangling limp from the ceiling. It was Joe and he appeared dead. His head was up in a tiny air pocket. Stan tries to pull Joe down from the ceiling but he was rigid and would not budge. While this is going on, the exhaust bubbles of Stan’s regulator inadvertently filled the air pocket with fresh air. Suddenly he noticed Joe’s throat moving as if gulping air and realized he was alive! When Stan jammed his hand up into the small air pocket he felt Joe’s face and found it still warm. Instantly, Stan took his long hose primary regulator and began purging -- adding more air to the little air pocket while he pushed the second stage into Joe’s mouth. Joe took the second stage and began breathing on it. After several long moments of gaining composure and breathing normal again, Joe relaxed and now easily dropped down from the ceiling. Stan found Joe’s mask locked tight in his left hand. He pried the mask from Joe’s left hand and placed it in his right hand. Joe placed the mask on his face and cleared it. Stan gave Joe the “OK” sign and Joe acknowledged it. Taking Joe’s right hand with his left hand Stan escorted Joe 150 feet/45 meters back to the surface of Cenote Ho-Tul. Stan saw Tom sitting next to Gus exhausted. They had just made it to the surface after both ran out of air during the last 30 feet of ascent. It was that close! Everyone was yelling that Fred was still in the cave. Gary was now down to 400 psi/27 bar and asked Carl from Team #1 who had 1500 psi/100 bar to follow him back down. Plunging through dirty water and the cave entrance the pair of divers swam as fast as they could along the main permanent guideline and returned to the location where Joe was saved. Swimming 30 feet/9 meters further they found Fred on his back, regulator out of his mouth and eyes glazed. They desperately tried to place a regulator into Fred’s mouth to no avail. Each gripping Fred’s shoulders, they pulled Fred 170 feet/52 meters back to the surface of Cenote Ho-Tul.

Everyone began peeling off Fred’s equipment, pulled him to shore and started mouth-to-mouth resuscitation. After five minutes of futile attempts from Gus (a Doctor) and Tom, everyone agreed to stop and accepted the fate that Fred was dead and all sat in the water and mud in sheer shock.

What Happened?

The next day everyone sat down at a table and each person was asked to recollect all the information about the dive. This is what happened according to all participants of the dive. When Tom was given the jump reel by Gary to reel up, he was nearing the “pink arrow” marker, and Fred stopped him and signaled him to put the jump reel back in place which Tom did. Then, both Fred and Joe began to swim upstream into “Paso De Lagarta”. During this discussion, Joe admits that he thought he was at the Cenote Ho-Tul at
that point of the dive and had re-calculated his thirds. Joe also stated he saw Gus turn around (when Gus began to follow Team #1) and thought that perhaps Stan had sent Gus back and interpreted that action as the wrong direction. Though it will never be known for sure, everyone came to the same conclusion that Fred was thinking this was the beginning of the “loop” to the Cuzan Nah. Gus stated that he knew they were still 300 feet away from Cenote HoTul and that the Cuzan Nah loop was in the opposite direction, but because Fred and Joe started swimming upstream the mainline of the “Paso De Lagarta” he figured he was wrong with his interpretation of the dive plan and lack of experience.

Tom stated that he did not realize there was a jump line installed on the way to the Grand Cenote. Remember, Gus had a video camera and both Fred and Tom were helping Gus by holding the video lights. The camera and lights, along with this being the first time in this cave system, distracted some when it came
to details.

So, the second team was now swimming upstream the mainline of the Rio Largata “thinking” they were on the “loop” section of the Cuzan Nah and expected to pass the first team at some point of this dive. Though the distance is difficult to calculate, judging by the amount of time, team #2 must have swam
at least 1000 feet upstream from the pink arrow marker. Finally, after 30 - 35 minutes of swimming Joe stopped and wrote on his slate asking everyone where was Team #1. Fred nervously looked at his pressure gauge and then “called” the dive as “strong doubt” was growing causing stress. They reversed order.
Everyone was now below 1000 psi/68 bar except for Tom who had 1400 psi/95 bar. On the swim out, they found a jump to the right which had a clip and line (similar to the jump involved with the Cuzan Nah loop.) They took the jump remembering the third cenote involved with the dive plan as they were getting low on air and becoming more scared. They swam 100 feet/30 meters and found an arrow marker pointing back to the mainline. The stress grew stronger! They turned around and swam back to the mainline. This action caused a four minute delay. Back on the mainline, one of Gus’s fin straps popped off the post causing a delay. Fellow members helped him with the fin. No one saw an arrow marker for quite awhile. Stress continued to grow and no one had a clue how far they were from Cenote Ho-Tul. Fred and Joe were now down to less than 500 psi/34 bar and very scared. At this point Gus ran out of air and went to Tom for air. Seeing this, both Fred and Joe were totally scared, swam past Gus and Tom and disappeared out of sight. Where Gus ran out of air is measured to be 600 feet/181 meters from Cenote Ho-Tul. Gus’s fin strap
popped off again and they abandoned the fin making swimming and sharing air even more difficult. After another 200 feet/60 meters Gus dropped and abandoned his video camera. (Both camera and fin were recovered by Stan the next day) Fred and Joe were swimming as hard as they can, very scared and breathing their precious air fast. They both ran out of air at the same place, 170 feet/51 meters from the surface of Cenote Ho-Tul. Joe told everyone during the discussion that he remembered an underwater cave rescue he saw re-enacted on television that took place in Florida involving an air pocket. Joe says he spat out his regulator and swam as far as he could when he spotted the tiny air pocket on the ceiling. That action gave him the two extra minutes when the group leader showed up saving his life.


This is a classic example of cumulative factors that led to this accident. The following observations help understand why this happened.

1. First time in the cave system for everyone except the group leader

2. The video camera and lights distracted several members of dive team

3. Complex dive plan

4. Inexperience for some members of the team

5. Change of dive plan not to surface at Cenote Ho-Tul on the return swim
from the Grand Cenote

6. Misinterpretation of the dive plan even though it was diagrammed on
paper and slate and reviewed a total of five times with everyone
agreeing they understood the dive plan (it still caused confusion). After
the fact, two members of the team stated they did understand the dive
plan, but were lulled into “following a leader syndrome”.


Date: APRIL 2nd, 1995.

Location: Sistema Najaral. Cenote Maya Blue (known locally as Cenote Escondido).

Victims: 48 years old, and a 36 year old male, both certified full cave divers from the State of Florida, USA.

The two divers were part of a group of seven spending a week diving the cave systems. This was the first dive of the trip. The group leader divided everyone into three teams. The plan was uncomplicated. Enter at “B” tunnel, swim 800 feet upstream and jump from tunnel “B” to “E” involving a five foot gap (this has been changed to 40 feet). First team of three divers arrived at the jump and found the “B” line pushed over the short distance and connected to the “E” line. This intersection lies against a huge rock. They referenced the “T” and proceeded upstream “E” line. The second team of two arrived at the junction and recognized the intersection. The third team of two (the victims), we assume, did not realize that an intersection existed and followed the lights of the first two teams, casually making the 90 degree turn in direction. A short distance later the third team called the dive on air (thirds) and turned around for
the exit out of the cave system. At the “T” intersection, the two cave divers followed the string that appeared to shoot straight right from the rock (this is known as a “blind” “T” intersection) causing them to swim in the wrong direction. One hundred feet further the “B” tunnel became dramatically smaller compared to most of the “B” passage that is quite large. However, they followed the upstream “B” line to the very end that included a minor restriction and made a “visual jump” to the “A” line tunnel and followed the clearly distinctive arrow markers headed out of the cave. Two obvious clues were evidently not recognized by the victims telling them they were going in the wrong direction before they got to “A” sediments or silt trail in the crystal clear water and the minor restriction. Both should have been “red” flags, in warning the cave divers something was wrong. Meanwhile, the first two teams had reached
their thirds upstream the “E” line passage called their dive and exited the cave system without incident. At the surface, a non-diving member of the group informed the divers that the third team never exited the cave. Quickly, the group leader recognized the problem and with another member from Team #1 entered the “A” tunnel and swam upstream as far as their air allowed on thirds from the first dive which was only 400 feet . There was no sign of the lost third team but at the point of turning around they noticed a cloud of silt that obviously had been stirred by the victims. From this evidence, it is speculated that the third team became totally scared and lost and decided to retrace their steps back to the “B” tunnel. Some divers familiar with this accident concluded the lost team followed the “A” line all the way to the end which at that time was beyond the “natural daylight”. We will never know for sure what really happened. What we do know is the “lost” team followed the “A” line upstream as far as they could until their air expired and they both unfortunately drowned.


Not paying attention to details as you swim into a cave system and not recognizing features on the return swim causing confusion. Referencing can save your life!

Date: AUGUST 17th, 1995.

Location: CENOTE CALAVERA (Cenote Esqueleto/Temple of Doom.

Victims: Male adult certified open water diver from Norway, a female Divestore owner from Cozumel and a 55 year old female open water certified diver from Colorado, USA.

This tragic accident began as a dive store organized trip from Cozumel. The store owners had heard about the beautiful cenotes and received inquiries about cenote diving from customers. They decided to schedule a trip and hire a local Divemaster who had previously lived in the village of Tulum and was familiar with the local cenotes. He was not certified in cavern or cave diving, nor was he
a “qualified” guide. With five paying customers, the group traveled to the Grand Cenote located five kilometers from Tulum. The group of eight made the dive and thoroughly enjoyed the dive without incident. The spectacular beauty, shallow depths and crystal clear warm water had everyone enthusiastic and the “hook of trust” was now in place with their guide. They decided to

drive down the road to the Cenote Calavera (known locally as Cenote Esqueleto) to make a second dive. Entering the cenote, the dive master’s overconfidence took control and instead of taking the group on the traditional cavern tour, which consists of a 360 degree permanent guideline (all easily within the sight of natural daylight), he took the group of eight into the passage known as the “Madonna” and into the cave system. The last member of the group (The male owner of the dive store) became very stressed and bailed out, and returned to the surface. This passage is very large and brilliantly white making it very easy to swim and follow a guideline. The group continued further into the cave with the divemaster leading. After swimming approximately 250 feet/75 meters in, two members of the group became very uncomfortable and turned around to exit. The divemaster was totally unaware of this. Further into the cave the three remaining members became stressed, not knowing how far they were from the cenote and were now getting low on air. Confusion and stress contributed to the situation as everyone was now desperately trying to swim back to the cenote. The three victims ran out of air at the beginning of the “Madonna” passage. The divemaster managed to make it back to the surface and obtained the scuba tank from the dive store owner who bailed out at the start of the dive. Returning to the “Madonna” passage the divemaster found two divers dead but brings the wife of the divestore owner back to the surface. They were able to get her out of the cenote and rush her to the Red Cross station in Tulum where she died. This information was obtained through local police officials.

Not using a professional, qualified guide was the first major mistake. As a dive store trip with paying customers, this was totally unacceptable and inappropriate. Too many people on the dive caused confusion and difficulty to manage. (The maximum ratio with a professional guide is FOUR) Going beyond “natural daylight” into the cave system was the second MAJOR
mistake along with unsafe management of their air supply.


My Mother, Judith Marshall died along with two other people on August 17th, 1995 at the Temple of Doom near Quintana Roo, Mexico. She was a certified open water diver. She was very interested in visiting the cenotes because of their beauty and their archeological significance. She was a grandmother, mother, sister, friend and teacher. Many people will remember her, especially her children and the little children she taught throughout 20 years of teaching.

The dive guide, who was contracted by the dive store, led a group of eight, past the cavern zone into the cave. The party included the dive store owner. The dive store owner abandoned the group and did not complete the dive. The dive store owner and divemaster were absolutely unqualified to organize and lead a cave dive. They were not certified cave divers. They led my mother and the other divers to believe that they were qualified instructors who would protect them. The dive store owner and divemaster made terrible mistakes which led to the deaths of three people and could have killed the other divers as well.

The scuba diving community has worked hard in the last few years to make diving safer in Mexico. This tragedy was the result of the dive store’s lack of knowledge and very poor judgment. They should never have gone past the cavern zone into the cave. Cave diving is only for certified cave divers.

If you are involved in any capacity with scuba diving, please check the certification of anyone involved in each dive. If you are a landowner, please prohibit unqualified divers from diving on your property. If you are a dive store owner, check the certification of your customers as well as your employees. If you are an Instructor, please do not attempt dives which are beyond your level of certification.

I am writing this letter in remembrance of my Mom. I will miss here more than I can ever say. She’ll never see her granddaughter grow up. I hope that writing this letter influences someone to do his or her part to prevent another tragedy like this one. Out of respect for my Mom’s wonderful, generous life and her tragic death, please do your part to prevent another tragedy.

Most Sincerely,

Jennifer Forrester

Date: DECEMBER 24th, 1996.

Location: Sistema Najaral. Cenote Cristal known as Cenote Naharon within the diving community.

Victims: 46 yr. old and his 22 year old son -- open water certified divers From Orlando, Florida.

It was the day before Christmas when this family of mother, father and sons 18 and a 22 year old wanted to spend a relaxing day enjoying the beautiful Cenote Cristal (Naharon) swimming and picnicking. The father and eldest son brought with them their open water scuba equipment. (This particular cenote
is not popular or recommended for open water diving because of the very shallow depths -15 feet/4 meters or less - and relatively small size) The Father decided to take his son into the cave entrance known as the cavern zone. This cavern is NOT very popular because the walls and ceiling are coated a very brown color from tannic acid that exists in the cave system. This absorbs light beams and makes it more difficult to see objects from a distance. Not using a guideline, the pair swam into the cave. From the silt stirred by the divers, it is calculated they swam approximately 200 feet/60 meters into the cave area.
Because they were improperly over weighted (using weight belts meant for open water salt water diving) they swam feet down and disturbed massive amounts of sediment which blocked the “natural daylight” from the cave entrance and their exit. This caused a heavy dose of fear and the pair got separated. The

Father managed to find his way back to the cave entrance but was critically low on air. Realizing his son was still back in the cave he made an attempt to swim back to look for his lost son, but exhausted his air and drowned at the entrance. The son was found next to a warning sign (that is written in both English and
Spanish warning divers not to go further unless cavern or cave certified) with 600 psi/41 bar remaining in his scuba tank. This indicates that because of very high stress, rapid, shallow breathing was taking place that does not allow a good exchange of oxygen in the lungs thus causing the carbon dioxide to rise to a
dangerous level pushing the diver to unconsciousness. The son’s body was recovered by a full cave certified diver from Tulum. Information was obtained by the recovery diver.

Reviewing “Accident Analysis” the following rules broken were: 1. Not trained for the “overhead environment”. 2. Did not use a continuous guideline. 3. Did not plan 2/3’rds their air supply to exit. 4. Did not use three lights.

Date: APRIL 16th, 1998

Location: Sistema Sac Aktun. The Grand Cenote.

Victim: Young male adult certified open water diver from central Mexico.

The victim and a group of six on Easter Holiday were brought to the Grand Cenote by one of the members in the group who had already dived the Grand Cenote on a previous visit and was attracted to the very clear water, shallow depths and the spectacular decorations. No one was cavern or cave certified and a professional guide was not hired. They entered the cavern area and began touring and exploring. The cavern zone of the Grand Cenote is very complex with many small passageways leading off from the “main” area. The victim found a tiny passage on the northwest side where he entered without a guideline. Going further in he quickly stirred a massive amount of sediments and created very poor visibility. He could not find his way out, exhausted his air supply and drowned. The body was recovered an hour later by a full cave certified diver who happened to be there diving for pleasure.


The victim broke four of the five rules of “Accident Analysis”. 1. Not trained for the “overhead environment”. 2. Did not use a continuous guideline. 3. Did not plan 2/3rd’s their air supply to exit. 4. Did not use three lights.

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Steve Gerrard
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Cenotes of the Riviera Maya
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