All cave divers have one thing in common: they’re wired weird. I figured this out one warm February morning, as I followed Bill Rennecker, my cave instructor, into a north Florida cave system called Little River. We were well on our way to the Dome Room, and I had slowed momentarily to check out what seemed to be a fossil in the scalloped wall. When I looked up, Bill was several feet ahead and, not wanting to hold up the parade, I began a vigorous pull-and-glide against the system’s inexorable outflow, aiming for the luminous backwash of Bill’s light.
Cave diving attracts a special breed of under-water enthusiast—one that likes dark, sometimes small spaces and can’t wait to see what’s around the corner.
What goes through one’s mind at a time like this? In my case, the first thought was, 'Well—I’m certainly not the poster child for cave conservation this morning.' And my second was, 'Boy, is Bill ever going to be cheesed when he sees that I’m plugging up the only way out of this cave.'
Cave and Cavern Training Agencies|
—International Association of
Nitrox and Technical Divers
(305) 751-4873 • www.iantd.com
—National Speleological Society
(256) 852-1300 • www.cave.org
—National Association of Cave Divers
(888) 564-6223 • www.safecave diving.com
—Technical Divers International
(207) 729-4201 • www.tdisdi.com
Cave and cavern diving is a specialized type of training that you should think long and hard about before seeking. If you can see predicaments as interesting problems requiring solutions, you just might be wired weird enough to go dancing in the dark. And if you’re not, you should know beforehand —this ain’t the PADI Underwater Naturalist Specialty Course. All cavern and cave diving have four things in common: the diving is done in an overhead environment (no immediate access to the surface); ambient light is assumed to be limited (or, in the case of cave diving, non-existent); the sudden loss of visibility (from silt-out or blackout) is assumed to be both possible and probable and, since surface air, the ultimate back-up supply in most diving situations, is not readily available, conservative air management is crucial.
So why take such training? One readily apparent reason is that it’s mandatory if you want to visit caverns or explore caves. Parks and property owners in cave country will often require proof of training before allowing divers with lights into caverns or before allowing anyone to enter a cave.
But there are equally valid reasons for seeking such training, even if you never expect to set foot—er, fin—into a cave once you’re certified. Cave-diving techniques adapt very well for wreck divers planning to extend their penetrations beyond the limits of natural light. And the guideline-use and zero-visibility training that are part of every cavern course are useful skills for rescue divers, search-and-recovery divers or anyone planning to dive in less-than-optimal visibility.
Cavern training is generally done in conventional scuba gear, augmented by line reels and at least two lights per diver. Training in line-reel use begins on dry land and then proceeds to open water, where divers are “blindfolded” (often with aluminum foil over their masks). Finally, after classroom instruction on the do’s and don’ts, the field work goes into a cavern, where the divers proceed no further than the limits of natural sunlight and 130 linear feet of travel from the surface, and students are introduced to gas-management principles, such as the Rule of Thirds (use no more than one-third of the air supply going in, use one-third coming out, and save one-third for emergencies).
Once cavern diver status is achieved, divers can proceed to a Beginner Cave or Introduction to Cave Diving course, in which a single tank with redundant valves is used, two independent regulators are employed (one with a seven- or nine-foot hose), multiple line reels are used, and each diver carries at least three lights, one of which has to have an output equal to a 35-watt incandescent bulb. This training is performed in simple systems with no complex route-finding situations and no traverses (in one aperture and out the other). When done, the novice cave diver may continue to dive such systems, provided he or she is sticking to mapped and lined passage and not exploring.
Finally, in Full Cave training, divers move up to doubles sets, usually with isolator manifolds (European cave divers often train with independent doubles). And here, the travel becomes more complex, making traverses of systems, using gap reels to bridge spaces between one route and another, route-finding and mapping passages.
Along the way, cave students can expect to identify and rectify mistakes made deliberately by their instructors, successfully extract themselves and a buddy from a cave with no lights while sharing air and successfully perform a “crawl-out” after simulating a complete loss of buoyancy (an experience that demonstrates that all that equipment can feel darn near as heavy underwater as it does topside).
Nevertheless, cave training is not the go-gently-anyone-can-do-it experience that recreational scuba training has become. The major purpose of cave training is to prevent deaths (before standardized cave training, literally dozens of divers perished in caves—just in north Florida—every year). And part of the way it does that is to identify claustrophobic or panic-prone individuals under manageable situations, de-selecting them before they can lead themselves or others into trouble. Not everyone’s wired quite weird enough to be a cave diver. If you are, cavern and cave training can open you up to a whole new world, as well as make you a more confident, visibility-optional diver.
Adventure-travel and scuba writer Tom Morrisey is also an NSS-CDS-trained Full Cave Diver and a PADI Cavern Diver Specialty Instructor.