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The Risks

 Cavern and cave diving in cenotes offers a compelling fascination and beauty that stimulates the passion for a unique and pristine environment.  Understanding the risk when voluntarily exploring or touring this overhead environment is vital to the confidence and enjoyment along with having control with the success and objectives of the dive.  A good diver recognizes and accepts the hazards and the benefits when dealing with the risk.  

What are the Risks?

     A variety of factors all contribute to understanding the risks. The psychological power, the manipulation of discipline, equipment configurations, controlling the pressure of stress, the hazards of decompression, and handling the potential of an unknown emergency are risks.  The safe diver recognizes the limitations and capabilities of himself or herself.  Risk management is knowing what you can do, performing with efficiency and establishing positive objectives.

     The psychological aspects begin with attitude.  It is your mental outlook towards whatever you wish to achieve or obtain as a goal.  A good attitude's foundation is built with the knowledge about the skills you need and the environment you desire to explore.  With training, practicing skills and gaining experience the safe diver develops confidence. This allows you to be comfortable and enjoy the dive and the cave or cavern.

     Discipline must be learned through the ability to react to situations centered on common sense and logic.  You develop your abilities to the level of automatic response by practicing and making everything reach to a point of reflex behavior.  You are responsible for your own actions and self honesty knows how to live within your own limitations.  Being dependent on yourself, if and when you have a problem, is you correcting or dealing with it, no one else.  Your "little voice" is that sixth sense developed through time and experience that tells you how and when to make a dependable decision.  The only way for you to develop this sense of intuition is to be fully aware with all the risks involved in the task at hand.

EQUIPMENT CONFIGURATIONS

     As with all aspects of scuba diving, cavern and cave diving is an "equipment dependent" activity.  Because it is a very specialized part of diving it is considered very advanced and technical.  One cannot perform any type of exploration of the underwater cave environment without the proper equipment and knowing how to use it safely and efficiently.  They are the tools that allow access and opportunity.  Equipment configuration is the heart and soul of doing it right and successfully.  Without it done correctly, it cannot be accomplished.

     Because the diver relies on his or her equipment as a means of life support, comfort and success, major emphasis on how it is used, what is used and where it is located makes a tremendous difference.  Efficiency, air consumption, comfort zone, distance traveled, tasks performed are all dictated by the use and configuration of the diver's equipment.  It is very important to place special emphasis on equipment configuration at the beginning of an individual's participation in cavern and cave diving to insure the optimum results of good habits, success and enjoyment are achieved.

     It is equally important that the diver's equipment is not a threat to the cave environment.  Breakage of formations and scars are forms of destruction because of carelessness and lack of awareness with equipment placement.  All caves show signs and evidence of damage from the diver's equipment.  The better the diver is configured, the less opportunity for this harm to occur.  The delicate and fragile decorations and formations of the cenote/cave system command the ultimate in the cave diver's ability and attitude.  Safety is paramount, proper equipment configuration greatly increases the odds in obtaining this objective. Damage or equipment failure is highly reduced when special care is enforced.

     The following terms and statements must be the primary objectives of every safe and properly equipped diver.

KEEP IT SIMPLE

     By habit or human nature, we have a tendency or desire to complicate things way beyond necessary or required.  It is very easy for divers to carry or bring items that are not needed or used.  BELIEVE IN THIS STATEMENT:

                  "IF YOU DON'T NEED IT, DON'T TAKE IT!"

     Memorize it, worship it, and trust its meaning, as it really works! Simplicity allows fewer problems, less stress, more enjoyment and better success.  Because it costs more or its "cool" to wear or use does not mean it is best for you.  More junk is worn by divers that really inhibit the safety and pleasure of the dive.  The performance and efficiency is greatly enhanced when less is used, smaller means better and less drag and weight controls the dive more effectively.

NO DANGLIES

     If anything hangs below the horizontal profile, it is a dangly.  Take a pencil and hold it horizontally.  That's your swimming profile.  If anything hangs below that profile, it's a dangly.  Correct it!

STREAMLINING

     Swimming through the cave environment is usually a constant motion. Two major obstacles are drag and vulnerability.  The routing and positioning of regulators and hoses, the location of safety/back up lights, reels, pressure gauges, inflator hose(s), primary lights and the presentation of the backplate/softpack harness play a major role to this need.  Hoses should always point downward and inward best as possible. Of course, this will fluctuate depending on the style or engineering of the first stage.  Multiple choice first stages should be low profile.  Hoses that stick out or more prone to be damaged or will fail with collisions from the cave ceiling, walls or restrictions creating opportunities for a serious problem or accident.  Protection is a necessity to minimize this risk.

     Small safety/back up lights is preferred because it is easier for storage and creates less weight and drag.  Many cave divers locate their lights on the shoulder harness clipped to a "D" ring and held in place by a form of retaining strap or surgical tubing.  An alternate site for your safety/backup lights would be the pocket on the waist or chest strap.

     All reels are usually carried on "D" rings placed on the waist strap as close to the back plate/soft pack harness as tolerated.  This allows close proximity and accessibility.  Pressure gauges are kept close to the body with a clip and/or surgical tubing.  Combo gauges are discouraged as they create a longer profile, more drag.  Some divers prefer to place the pressure gauge strapped to the inner arm for easier viewing.  Brass gauges are more durable than plastic housed gauges.

     The low pressure inflator hoses can be placed close to the body with surgical tubing, threaded through "D" rings or kept under the arm.  The corrugated high volume hose is worn over the shoulder for easy reach.

     Primary lights usually involve a water proof battery pack with a chord leading to a light head.  The battery pack can be worn on the waist strap positioned close to the back plate or directly attached to the back plate with clips or keepers.  It should be worn snug and not loosely and not be able to move or slide forward.  The style of butt mount positioning is becoming less popular and poses more of a hazard going through restrictions.

     Back plates are the most popular and preferred harness system for the use of double tanks on the back.  They are rigid and durable allowing the nylon webbing harness to be positioned in a dependable manner. Back plates first evolved during the mid-1970's by such individuals as Florida cave divers David Manor and Greg Flanagan.  Because of the optimum characteristics of the back mount "wings" buoyancy devices, the back plates provide low profile and better stability.  It creates a flexible choice for the length of the shoulder, waist, chest and crotch straps and location of "D" or circle rings and various forms of tubing for comfort and positioning of equipment.  And it allows more freedom in the front area for swimming, positioning and carry extra equipment such as stage, decompression or oxygen/special gas cylinders or the specialty items.  Soft pack harnesses have just entered the market in recent years.  They offer an alternative selection with the objective aimed at comfort.  Different brands provide different styles.

PLACEMENT

     This term means position and location of any piece of equipment. Whether it means right side up or upside down, sideways, below or above, top or bottom it is controlled by easy accessibility, protection and personal choice.

KEEP IT CLEAN

     A phrase coined by veteran Florida cave diver/explorer Bill Gavin.  It means simply remove any item that can be a potential nuisance or hazard problem.  Particularly when negotiating restrictions or obstacles that force the diver to be close to the guideline.  With reduced visibility or limited space to operate within and having a buddy assist you the diver does not need to complicate matters with unnecessary factors compounding the situation.

                   Suggestions to follow:

                   1.     Remove regulator or valve caps or covers.

                   2.     No whistles.

                   3.     Shorten or remove pull chords BCD dump/overpressure

                           valves.

                   4.     Eliminate or minimize item(s) that hangs out or creates a

                           dangly.

EASY, AUTOMATIC ACCESSIBILITY (EAA)

     Every diver's aspiration should be to build an automatic response to any piece of equipment during any part of the dive.  Practice, practice, practice helps increases the odds of a quick reaction without any mistakes or delays especially during a stressful situation or emergency.

USE COMMON SENSE

     Over learning skills is a "key" component in acquiring common sense. By definition, common sense is "sound prudent judgment".  To have common sense - a base of knowledge, understanding risk analysis and technique.

BE SELF SUFFICIENT

     The ability to accomplish any need or emergency upon yourself without the assistance of another diver.

PERSONAL PREFERENCE

     It means there are several styles or methods to choose from.  All work well, some better than others. The diver must pick what is best or suits his or hers taste for safety, accessibility and comfort.

PROPER WEIGHTING

    Eliminating or minimizing unnecessary weight.   The less weight the better!  Positioning weight properly to achieve the best swimming posture and buoyancy control. Factors can be influenced by salt and fresh water, temperature of water, equipment used and personal body characteristics such as weight and height.

USER FRIENDLY

     Equipment that is easy to understand and work with.

QUALITY EQUIPMENT AND DEPENDABLE PERFORMANCE

     Your life depends on the best equipment and most reliable performance. That is why it is called life support equipment.  Cave divers demand the optimal of all selections of equipment available.  Always seeking for better ways to enhance and provide the safest approach and most success in their goals of exploring the overhead environment.

CARE AND MAINTENANCE

     A critical point in the development and performance of the diver.  One must understand and dedicate the discipline in properly taking care of their equipment and provide the consistent maintenance necessary to insure reliable and dependable use and performance.

CONTROLLING THE STRESS

     Stress is pressure from an outside force that can you feel tense inside. It is part of our lives everyday.  It operates at every level of our behavior with the ability to breakdown the performance of the individual.  Every day and every moment can the tension can impair an individual's breathing, confusion can evolve and propulsion skills become erratic. This pressure can increase heart rate and make an individual's internal chemistry fly around as if butterflies.  This effect can strain or deform the diver's control of his/her environment and his/her accomplishment.

     The only way the diver can develop stress tolerance is practicing and mastering the specific skills and techniques necessary to safely prevail.

     Understanding that experience is the best teacher built slowly through time and repetition.  Anticipating the unexpected is one tool that minimizes the anxiety.  By gathering as much information and organizing a plan from both a group and individual point prepares the mental readiness.  Through visualization and simulation, the diver focuses on the tasks and increases the odds for successfulness. Over-learning is another tool to minimize anxiety. Practice, practice, and practice is one solid method in achieving this goal. Being intimately familiar with your equipment is another way to cope with stress. Your internal physiological control is regulated through inner self techniques and biological feedback. All of these different approaches present methods to tolerate the many levels of stress.  

Thinking under stress

     The first thing anyone should do when a problem arises is STOP.  This action halts the situation from getting worse. Breathe in and out several times.  Maintain control.  Analyze the predicament, figure out what course of response to correct the situation.  Solve the problem.  Review and evaluate the dilemma.

Concentration

     With self discipline, handling stress does not become an obstacle.  Your choice is simple.  Live or die.  When faced with a challenge, choose to deal with the problem.  Think positive!  You will be surprised how easy it is to come through with a big smile on your face.  Either way you take it, you are right.

     Decompression sickness is an affliction that involves gas bubbles forming anywhere in the human body. The bubbles become a problem from improper decompression during ascent.  The degree of severity depends on location and the symptoms involving the development of the bubbles. This range of harshness can be mild or irritating to sharp discomfort or pain including paralysis and/or death.

     Individual tolerance plays a major factor.  Age, physical condition and stamina, diet, hydration, rest, body fat and personal habits impose how one handles bubble formation and the prevention.  Other factors that contribute to the formation of bubbles:

     Rapid ascent rates and dehydration are the greatest factors that contribute to decompression sickness. Ascent rates are part of the decompression profile.  Following specific ascent rates are critical in successfully avoiding bubble formation.  You breathe the gas in through the lungs with gas exchange occurring between the cells and blood.  The inert gas flows with the blood and disperses into the tissues.  When you ascend the pressure decreases and the gas must diffuse from the tissue to the blood and back to the lungs where it can be expunged from the body.

     Not quite so simple.  This course is perplexed because of the length of time at depth and the quantity of gas absorbed into the tissues. This gas MUST be released very slowly from the tissues to avoid DCS.  If the difference between tissue gas pressure and the ambient gas pressure exceed certain parameters, the gas will not stay in solution and bubbles will form.  Ascending very slowly by monitoring and controlling the ascent rate by decompression stops will increase the advantages for completing a safe dive.

     Hydrating your body with fluids is critical in minimizing the risk.  Water is the very best homogenous mixture.  Factors that contribute to dehydration include not drinking enough water, consumption of alcohol, sweating, caffeine, breathing dry air or gases, long dives and long decompressions, and losing fluids as you breathe. Soft drinks, coffee, tea, juices are not the answer.  Plenty of water.  Force yourself to hydrate the body properly. Be extra careful in tropical climates such as the Yucatan area.

     Strenuous exercise should be carefully disciplined as too much before, during and especially following a dive is hazardous. Some exercise or movement during decompression is considered affective with circulation and a benefit. Cavitation is caused by rapid movements of the body's limbs.  Sudden pressure change because of high flow of water exiting a cave or loss of buoyancy may produce bubbles.  Alcohol is bad because it causes vasoconstriction of blood vessels and kills brain cells from an increase in blood lipids.  Smoking tobacco places carbon monoxide into the blood circulation which inhibits the exchange of gases and increases the chances of bubble formation.  Using any forms of drugs - legal or not - is stupid while under the power of higher partial pressures.  If one must use any over the counter drug such as decongestants learn to understand the effects on the diver's physiology and what problems they may cause towards DCS. Extreme temperature changes can be a factor with DCS. Luckily, the water temperatures of the cenotes are constant and do not pose such a threat.  And, of course, hot showers immediately after dives are not smart.  Restrictive equipment or previous injuries impede circulation that may create bubbles. Be careful with tight fitting wetsuits/dry suits and any straps from harnesses. Be sure they are snug and comfortable.

SYMPTOMS OF DECOMPRESSION SICKNESS

PREVENTIVE MAINTENANCE

     1.     Perform rate of ascent exactly prescribed by the decompression

            profile.

     2.     Drink plenty of water twelve hours or more before diving.

     3.     Drink water immediately before and after the dive.

     4.     If you smoke, avoid a few hours before the dive.

     5.     Do not drink any alcohol twelve hours before a dive and minimum

             four hours after a dive.

     6.     Do not do any strenuous exercise before and during the dive.

     7.     Avoid exercise immediately after the dive.

     8.     Do stay at the surface for fifth teen to thirty minutes before any   

             vigorous exercise after the dive.

     9.     Wear wetsuits/dry suits that provide good insulation and comfort.

             weights or exercise machines.

     11.    Minimize the levels of obesity.

     12.    Be conservative with age.

     13.    Avoid fatty foods.

     14.    Endure fixed during decompression stops.

     15.    No flying for at least 24 hours after a dive.  

     There are no guarantees that by following all the recommendations and advice that avoiding decompression sickness is assured.  Once the risk is understood then following the procedures and preventive actions will increase the odds tremendously in minimizing the risk.

     Risk management includes knowing how to handle an emergency situation.  Training is the best method to control the risk exposure and acquiring total respect for the cave environment.  The safe diver knows how to identify particular behavior that may cause incidents or accidents. Being familiar with former accidents and studying viable emergency situations is the correct direction to prevent these actions to happen.

     Who is at risk?  New and inexperience divers are the highest risk.  Lack of experience and now being familiar with past situations to better understand and manage a problem makes a huge difference.  As divers gain experience their ability to control an emergency becomes better. Experienced divers are usually in poise but can easily become a higher risk because of being cocky or overconfident.  They can turn complacent and take things for granted if not being careful which can result of making mistakes.  Divers can fail to anticipate problems because of laziness.  They can be lulled into a false sense of security when things are going too smoothly.  Overconfidence in their equipment, the cave or cavern and in them can lead to errors.

     Emergency situations includes light failures, line entanglements, line breakage, equipment failure such as second stage free flow or first stage high pressure failure,  stress, confusion with intersections or jumps/gaps, lost diver, other divers, restrictions, loss of visibility, low or out of air, physiological problems and geological disturbances (example-rocks falling or sliding debris). Accident prevention is knowing how to recognize the dilemma, respond to the needs of the predicament and establishing and discussing the limitations of the dive. A safe diver does whatever it takes to minimize and control the risk.

Steve Gerrard lives in the Puerto Aventuras marina resort.  He has been safely teaching cave diving for twenty five years.  His favorite activity is underwater cave photography using the NIKON 100 digital camera with a Light & Motion Titan Housing using Ikelite strobes.  He is the author of the famous guidebook titled - THE CENOTES OF THE RIVIERIA MAYA and soon to be published  CENOTE DIVING - SAFE & FUN.   You can contact Steve at:

stevegerrard@cavediver.com  or  www.steve-gerrard.com