Safe Cenote Diving

Before diving a cenote you need to know the risks and your limitations. Any scuba diver who plans to dive a cenote should understand the difference between a safe cavern dive and an open water dive. Open water simply means any body of water using SCUBA which allows a direct ascent to the surface. A cavern dive in a cenote means diving into an overhead environment which does not allow a direct ascent to the surface. To safely dive the cavern zone the scuba diver should either be trained or certified as a cavern diver or participate in a cenote dive with a qualified professional cavern diving guide.

The international scuba diving training agencies such as PADI, NAUI, SSI, YMCA, PDIC, SDI, CMAS, etc. makes it clear no open water instructor may take a student into any type of overhead environment. Yet, despite the risks and warnings many open water instructors are taking their open water students into the overhead environment. This is a serious and direct violation of the international certification agency’s training standards and a potentially dangerous situation.

Another life threatening situation in the cenotes of the Riviera Maya involves open water divers not trained and certified in cavern or cave diving bringing underwater lights with them and venturing into the cavern and cave zones of the cenote. This unsafe conduct can lead to drowning accidents.

In the state of Florida, sinkhole and spring diving is very popular. One solution to the problem of unqualified divers going into the caverns and caves is the:

“THE NO LIGHT RULE”

All of the state parks, national forests, private camp grounds and several land owners who have underwater caves on their property apply this very successful rule of diving in the overhead environment. If the diver is not certified in cavern or cave diving, they are not allowed in the water with a light. When the diver arrives at these dive sites, posted signs and/or written waiver forms carefully explain this policy. Divers are asked to show their certification qualifications. Only qualified, cavern divers are allowed to take lights into the caverns or caves. This simple rule has helped reduced accidents and saved lives during the past twenty years. It is a huge success!

Cenote diving has rapidly evolved into a very popular type of diving for divers traveling to the Riviera Maya in Mexico. Simply stated, a cenote dive is a CAVERN dive, diving the "overhead environment" within the limits of natural sunlight. Following established guidelines will help make a cenote dive safe and easy to enjoy. Cavern divers should always stay within 200 feet/61 meters linear distance of the cavern entrance and go no deeper than 70 feet/21 meters in depth. Fortunately, all of the popular cenote dives in the Riviera Maya are very shallow.

A popular safety theme of "ACCIDENT ANALYSIS" is constantly emphasized. The key in safe cavern diving involves a continuous guideline (used as an additional safety navigational tool with the daylight), allowing 2/3rd's of your air supply to safely exit the cavern zone and using a minimum of three lights with the sunlight being your outside source and two battery powered lights (using one as your primary light).

ONE CONTINUOUS GUIDELINE - Most cenote dive locations have a permanently installed rope which serves as a great psychological reference. If no permanent guideline exists then the qualified cavern guide can temporarily install a guideline during the cavern tour. This string is a very important part of a safe cenote dive and should never be taken for granted.

AIR/GAS SUPPLY - The air supply must be managed. When a diver voluntarily enters the cavern zone it is imperative that he or she allow enough air to exit and plan for any unseen emergencies. The "classic" 1/3 air/gas in and 2/3rd's air/gas out has been an established procedure since the early 1970's.

The limitations of the cavern zone demand that all the divers exit with at least a minimum 1200 psi/80 bar, no less. This valuable cushion creates the time to safely handle an unplanned problem or delay when diving the "overhead environment". You can certainly continue your dive in the open water area to enjoy more of the beautiful cenote basin where many species of fresh-water
tropical fish, turtles and aquatic plant life live.

The Cavern Tour has quickly evolved into the hottest and most popular way for open water divers to have the opportunity to experience this unique and incredibly beautiful type of diving in the Yucatan cenotes. The dive should be organized around a professional, qualified guide. The guide must be Full Cave certified and should be a minimum Divemaster qualified. The guide should also be experienced in cave diving and be very knowledgeable about the local cenotes.

Because most diving visitors to the RIVIERA MAYA are on a one week vacation or a brief few days, this type of diving gives the chance to participate and witness a pristine environment without having to invest in more training and equipment. For those who are so enchanted and thrilled by this unique underwater world and wish to seriously pursue more, training is readily available in the form of cavern, Intro to Cave and complete cave diving training. This training can be accomplished in many different formats suitable to your time and comfort level.

The Cavern Diving Course

The cavern diving course requires a minimum of two/3 days of training developing the minimum skills and knowledge for safe cavern diving. The course describes the dangers involved with cave diving. It also covers planning; the environment, procedures, techniques, problem solving and other specialized
needs.

Problem solving covers buoyancy control, body positioning, emergency procedures, following guide lines, and swimming techniques. Specific emphasis is placed on silting, entanglement, disorientation, and equipment modifications for this unique environment.

Classroom instruction cover the contents of safe policies of cavern diving, the environment, accident analysis, psychological aspects, equipment, techniques, body control and emergency procedures. During the course both land and open water drills will involve the use of guidelines, following the guideline as a navigational tool, following the line with no visibility, and emergency procedures including sharing air.

A minimum of four cavern dives will be conducted using a minimum of three different caverns.

During these dives the following will be performed:

a. Safety drill (practice sharing air, check valves and equipment on each
dive).

b. Demonstrate proper buoyancy control and body positioning with
minimum weighting and distribution.

c. Demonstrate good propulsion techniques.

d. Guideline awareness and the use of the reel and line.

e. Enjoy and explore the cavern gaining confidence and being
comfortable.

The safe limits of a cavern are:

a. Natural daylight.

b. 200 feet/60 meters linear distance.

c. 70 feet/ 21 meters maximum depth

d. 40 feet/12 meters minimum visibility.

e. No decompression diving.

f. No restrictions.

Certified cavern divers must use all necessary equipment considered appropriate for open water diving but also include two battery powered lights and a reel and guideline. The snorkel is not necessary. The Cavern course, by far, is the most popular course.

The Introduction To Cave course is another two/3 days of diving involving 4 - 5 limited cave dives based on the single tank format. The course reviews the information provided from the cavern course and delves deep into safe diving philosophy along with allowing the student to see and experience the cave system beyond natural daylight. For those students who wish to complete
their cave diving training and use double tanks, the Full Cave course introduces complex dives using jumps, gaps and jumps, permanent intersections, circuit/traverse dives and decompression procedures. For those divers who know they want to pursue complete cave diving training and do all the training at one time, the one week cave diving course provides the opportunity.

Cenote diving is exciting and fun. The spectacular beauty and pristine environment awaits the open water diver. Experienced divers comment that the cenote dive was one of the best dives they have ever made. These SACRED WATERS will instill a new desire for fun and safe diving.

The popularity of the cenotes has transformed THE RIVIERA MAYA into a major destination for divers from all around the world. As more and more divers hear about and discover the tranquil beauty of these pristine “windows” to the underwater world, the number of divers will impact these precious and fragile ecosystems. Safety and awareness of the environment are paramount
in educating both the cenote guide and the visiting divers.

THE CENOTE GUIDE

The popularity of the cenotes has transformed THE RIVIERA MAYA into a major destination for divers from all around the world. As more and more divers hear about and discover the tranquil beauty of these pristine “windows” to the underwater world, the number of divers will increase the pressure and impact on these precious and fragile ecosystems. Safety and awareness of the environment are paramount in educating both the cenote guide and the visiting
divers.

Cozumel is regarded as one of the top five dive destinations in the world for open water reef and wall diving. The RIVIERA MAYA is considered the #1 tourist destination in the western hemisphere. Within that exists the world’s largest diving operation that supports and produces recreational divers throughout the Riviera Maya. Combine these two locations with the forty plus dive operations that operate within the Riviera Maya and you have a tremendous impact on the limited supply of cenotes that can accommodate an enjoyable, safe cavern tour. The following cenotes can offer potentially 13 cavern dives.

CENOTE CARWASH CENOTE CHAC MOOL
CENOTE CRISTAL CENOTE DOS OJOS
GRAND CENOTE CENOTE EDEN
CENOTE TAJ MAHAL CENOTE CALAVERA
CENOTE CHICKIN HA CENOTE
CENOTE DREAMGATE CENOTE CARACOL
THE BAT CAVERN CENOTE

It was Parker A. Turner who recognized the importance of a structured system for open water divers to have the opportunity to visit, dive and enjoy these beautiful cenotes during their brief visit to the Riviera Maya, Cozumel, or Cancun. As the first International Safety Officer for the National Association for Cave Diving Parker organized and established recommended standards for conducting SAFE cavern tours for open water divers. Parker’s clear vision for the future was obvious. He knew that the cenotes were magical and would evolve into a very special and popular environment for scuba divers to visit. Parker submitted a list of procedures of how a cavern dive for open water divers could be safely performed. Admirably, the diving operations recognized this and graciously accepted the recommended procedures. Today, it can be said that 95% of all diving operations and/or Open Water Instructors/Cavern
Instructors abide by these recommendations.

THE CAVERN TOUR

Cavern tours are offered by qualified certified full cave divers who have earned a minimum Divemaster rating in the leadership structure. The purpose of these standards is to assist the growing needs of professional open water scuba instructors, who guide recreational divers into caverns found in north Florida, the
Bahamas and the Riviera Maya of Mexico´s Yucatan peninsula.

LIMITATIONS:

1. Natural daylight and an unobstructed ascent to the surface

2. Maximum linear distance from surface: 200 feet

3. Maximum depth: 100 feet

4. No restrictions

5. No decompression

6. Minimum visibility: 40 feet

7. Guide ratio: It is strictly 4:1 maximum.

8. Minimum psi/bar to begin cavern dive: 2000 psi/140 bar.

9. Minimum tank pressure to exit cavern zone: 1200 psi/80 bar or 20 cu. ft.

GUIDE QUALIFICATIONS:

Following two are required:

1. Certified full cave diver and

2. Certified as a qualified, certified Divemaster.

2. Recommend being an Open Water Instructor.

The Guide must use full cave gear configuration. Double tanks are required for air/gas management, handling of potential emergencies and as an example to potential students. No single tanks with dual outlet valve or side mount configurations are allowed to be used by the Guide.

PROCEDURES:

1. Detailed briefing before each dive

2. Explanation and review of rules for cavern diving

3. It is not necessary to go through extensive equipment modifications for the
cavern tour because it is considered a controlled experience. Minor
changes may be necessary, such as the addition of alternate air source,
removal of snorkel, and proper weighting.

4. Use of the guideline is essential to ensure a safe dive and demonstrate
proficient skills. It is recommended that the guide demonstrate proper
overhead protocol at all times.

5. No diver participation is mandated

6. Definitions:

a. speleogenesis and hydrology

b. cavern/cave environment (unique and fragile)

c. accident analysis

d. problems

7. Techniques

Brief review of:

a. buoyancy control

b. finning techniques

c. light use and signals

8. Review of basic communications

a. “OK”

b. “Stop or Hold”

c. “Dive is over, exit”

d. “Out of air”

e. Instructor’s choice for additional hand signals

9. Dive Plan

10. Complete post dive review:

A Guide should stress that divers on a tour are under supervision and in a controlled environment. Urge the divers to participate in a cavern course if they wish to pursue cavern diving.

1. Equipment:

Equipment is the same as for a cavern course. Standard open water scuba equipment with two battery powered lights

Cavern Tour Briefing Recommendations

It is recommended that critical aspects of the following outline be incorporated into the dive briefing for cavern touring.

I. This is a Cavern Tour NOT a “course”.

II. DEFINITIONS:

Cavern - Limits

1. Area with ceiling and some visible light from the sun

2. Large with no restrictions

3. Minimum visibility of 40 feet (12 meters)

4. Depth: Recommend 70 feet (23 meters) or less

5. Penetration: Maximum 200 linear feet (65 meters) from an opening

6. No decompression

Cave.

1. Beyond the sunlight zone

2. Extensive training is required: (A course takes a minimum of 7/8
days.)

3. Different equipment is necessary: (Double tanks, redundant
equipment)

III. ENVIRONMENT

Unique and fragile.

Dive gently.

Conservation.

1. Take nothing

2. No grabbing or pulling on speleothems

3. Try not to touch sediments

IV. GEOLOGY

The Yucatan peninsula is limestone rock.

1. Ancient sea bed

2. Sedimentary layered rock

3. Porous

4. Erosion from water forms the passageways

5. Speleothems form during dry periods (ice ages)

V. TECHNIQUES

Buoyancy and propulsion

1. Minimize weight (buoyancy check before the dive)

2. Neutral buoyancy

3. Gentle kicks from the knee and ankle, not the hip

Body positioning

1. Slight head down, feet up

2. Midwater positioning (stay off the bottom, away from the ceiling.)

VI. COMMUNICATIONS:

Light signals

1. OK: circle

2. Attention: wave light slowly side to side

3. Emergency/Assistance: rapid waving of the light

Hand signals

1. OK 4. Air status 2000 psi/1200 psi (140 bar/80
bar)

2. Stop/hold 5. Out of air

3. Turn the dive 6. Call the dive - Exit. (Any reason, anytime)

VII. ACCIDENT ANALYSIS

1. Training - if people have an interest in cavern diving it is
recommended they take a cavern course.

2. Guideline - continuous to the open water. Redundant reference
to the exit.

3. Air/Gas - 2000 psi (140 bar) to turn the dive. 1200 psi (80 bar) to exit the overhead environment.

4. Depth - maximum 70 feet (23 meters)

5. Light - minimum three lights: (Natural daylight and two battery
powered lights)

VIII. ADDITIONAL CONSIDERATIONS:

1. Equipment check, bubble check

2. No snorkel, no knives

3. Do not swim under the guideline

4. Halocline (some divesites)

a. saltwater is below the halocline, fresh water is above.

WHY THESE RECOMMENDATIONS

Safety is always the first issue for anyone who recreationally ventures into a “high risk” environment. If there is no understanding or control of the risk then accidents will become frequent and the danger of closing or denying access to the cenotes becomes very real.

Responsibility and image also play a very important role in maintaining safety and protecting these environmental wonders. If accidents occur or the cenotes become trashed or permanently damage then people will stop diving, snorkeling or visiting.

Any diver who takes other divers into an “overhead environment” MUST be TRAINED and QUALIFIED with a minimum amount of experience. Several deaths have been reported with unqualified guides.

Following the recommendations for qualified guides makes sense. It is not only for safety but for integrity and moral responsibility. Any compromise is unacceptable. Those who wish to dive the cenotes on their own should seek training and become a certified cavern or cave diver. Another approach is not to take a light with you on the dive. THE NO LIGHT RULE in Florida, USA has
made a major difference in minimizing accidents or close calls.

The land owner has a major responsibility to safety and protecting their fragile cenotes. Only the land owner can enforce the rules and regulations for safe cenote diving. Only the land owner can provide the access and use to the cenote which allows safe entry into the water and minimal impact on the cenote environment. The land owner must be responsible for SAFETY and PROTECTING the cenote, particularly when they make money from people using the cenote. Several of the land owners have done this. But, much more can and must be performed. The responsibilty belongs to the land owner.