SAFE CENOTE DIVING - PART II

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Stevegerrard

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Location
United States
# of dives
5000 - ∞
by STEVE PENN GERRARD

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.
3. 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 responsibility belongs to the land owner.
 
The rules are usually followed by most folks. Unfortunately, there was a drowning at Cenote Calavera located 2 km from Tulum, Mexico involving an open water diver on March 1st. I am still trying to get the facts on what really happened.
 
That is sad news indeed. I was diving in Calavera just a year ago and it is absolutely among the most memorable dives of my life. Would be interested in knowing what happened as well. In retrospect, I must say my guide back then followed these recommendations pretty well, except maybe for the three lights rule. When conducted safely and conscientiously the cenotes can be absolutely stunning and I cannot but recommend them to anyone who think they would feel comfortable in such an environment, knowing that there are incursions of overhead diving and possibly sometimes narrower passages requiring careful buoyancy control involved. But I agree that the risks must be acknowledged, and though I admit I may have been a tiny bit reckless not finding out about these guidelines before my own trip I'm certainly glad to find out they exists.
 
Is the rule above that guides may not use sidemount but have to be in back mounted doubles still in place? If so, why? I see the majority of guides diving sidemount these days, and can't really find anything wrong with the practice.
 
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