Ins and Outs of Cave Diving

By Jeanne Bear Sleeper

Since prehistoric times people have been fascinated by caves. Our ancestors found shelter and water, recorded the history of their day, performed religious ceremonies or crawled and climbed to uncover the mysteries of the cave. These prehistoric spelunkers stopped their exploration when confronted with a completely submerged passageway. With the development of scuba, men and women today are exploring water-filled caves in pursuit of scientific knowledge, for adventure or pure curiosity.

Cave diving is an exhilarating, physically and mentally challenging scuba activity. It requires extensive equipment, training and experience to be safe. If cave diving is in your future, begin your journey by contacting the National Association for Cave Diving or the National Speleological Society; Cave Diving Section. These nonprofit educational organizations are dedicated to the safe study, exploration and conservation of caves. Open water certification agencies, such as NAUI or NASDS, also offer specialty cave diving programs that recognize, incorporate or piggyback on the NACD or NSS-CDS programs. Proper training is essential before you attempt cave diving. The safety record of properly trained cave divers is outstanding. The grim fatality statistics of untrained, do it yourself, overconfident open water divers who attempt cave diving is frightening and tragic. Neither this article, books, nor years of open water diving are a substitute for training from a certified cave diving instructor.

There are many types of caves around the world, including coral caves, sea caves formed by erosion, lava tube caves and underground caves formed by the dissolution of certain kinds of sedimentary rock such as limestone and dolomite by slightly acidic, flowing groundwater. There are also sinkholes, cenotes, karst windows, sumps and underground lakes. By any name, they are all caves and require special equipment, techniques and training.

Caves are places of wonderment. There is a religious feeling that comes with hovering mid-water in a giant room surrounded by stalactites of white, yellow and orange. These columns were formed millions of years ago by dripping water, then flooded as the sea level rose. The scene reminds you of the grand cathedrals of Europe. Caves are home to species never found in open water and delight divers who discover the critters and aid in their identification and naming.

The Cave Environment

Cave diving involves unique hazards. There is no direct or sometimes even close, access to the surface. This ceiling makes you much more dependent upon your equipment, training and buddy.

Monitoring air supply is critical. Because an emergency swimming ascent is not possible and buddy breathing may not be an option, having an adequate air supply is mandatory. Normal open water reserves are inadequate. Cave divers have used the rule of thirds for years; use one-third going in, one-third coming out and save one-third as a reserve. For some types of cave diving, even more air than this is saved as a reserve.

Nearly all caves have a fine layer of silt on the bottom, walls or boulder tops. A brush of a fin, rush of water movement or a dragging gauge will disturb the silt and take the visibility from gin clear to zero in a flash. And it does not quickly settle out. A total siltout is one of a cave divers worst moments. Without a continuous guideline in hand, it can be impossible to find your way out. Cave diving courses teach head-down trim, precise buoyancy control and new fin kicks to reduce the chance of siltouts.

Specialty Equipment

A continuous, well laid line may be a cave divers most important supplemental piece of gear. This safety line starts either at the surface or the mouth of the cave and is periodically anchored throughout the cave penetration. This is a lifeline out of the cave in the event of a siltout or a light failure. Never disturb a float or line near a cave. It is not lost or forgotten. Some frequently dived Florida springs have permanent lines. Do not remove, reroute, add a junction to or cut these lines. And, if you are not trained as a cave diver, never follow these lines into a cave.

The reel and line used are specially designed for compactness, ease of one-handed use and reduced tangling. Plan to purchase a cave diving reel and new, continuous line when you take a cave diving class.

Other scuba equipment will need to be modified or purchased as well. Cave divers use twin tanks connected with a dual valve manifold; two regulators, one with a five to nine foot octopus hose; full exposure suit; three heavy duty, long lasting lights; full instrumentation; two masks; fins; cave reel and line; buoyancy compensator; knife and backup line cutter; slate; directional line markers; and compass. Extra clips and bands are needed to hold all the equipment close to your body. There is no need for a snorkel. One other essential is a trustworthy, dependable buddy with whom you entrust your life.

Summary

Because training is so important, this article does not contain how to do it instructions. It is merely a peek at what you will need as you begin an adventure that compares to few other explorations on earth. Training to become a cavern diver takes two to three days. Additional training to learn beginning cave diving takes another 8 to 12 days. At the end of the training you will have made 16 to 20 total cave dives.

NACD summarizes its philosophy with the commentary that there are no short cuts to safe cave diving. Sound judgment, the use of common sense and competent training, followed by patience in gaining personal experience is the only method of achieving the goal of safe cave diving.

For more information or to order books about cave diving, contact the National Association for Cave Diving, P.O. Box 14492, Gainesville, FL 32604 or the National Speleological Society; Cave Diving Section, P.O. Box 950, Branford, FL 32008-0950.

Acknowledgment

Special thanks to Jeffrey Bozanic, NACD and NSS instructor for his review and assistance on this article.