Many of the world’s best dive sites involve diving in overhead environments, often inside caves, caverns, sinkholes, and cenotes. Cave divers get the opportunity to experience sights that few humans have seen, sometimes in oceans, and sometimes in water filled caverns that were once dry inside. If you want to explore these places, you should be aware of the potential hazards that exist; despite special training and extra safety precautions, the risks are real.
Potential Hazards
Since 1950, hundreds of cave divers have perished for a variety of reasons; becoming disoriented and running out of air tops the list. In many caves and caverns, there is no access to surface air; instead of being able to swim directly to the surface, divers must backtrack or complete a loop, swimming horizontally toward the exit. Luckily for recreational cave divers, many of the world’s best caves have permanent lines inside that show us where to go.
In these popular caves, unmapped areas or areas with known hazards are often clearly marked with the sign of death – a skull and crossbones that warns divers not to enter. In caves without permanent lines or mapping systems, there are no such signs and one must rely on training to make decisions about where to go.
Another hazard, and one which has led to disorientation and diver deaths, is the loss of light. Inside the earth, where no natural light penetrates, you’re blind without a light, and you could be thousands of feet from the entry. Even on simple cave dives, it is important to carry a primary light and two backup lights; the best often let you experience unlimited visibility. If you have not planned properly, and you’re missing back up lights or batteries, do not enter a cave. Save it for next time, and be thankful for the opportunity to learn an important lesson.
Failing to follow safety rules regarding air usage is another mistake divers have made. Exiting caves can sometimes take as much, or more air as entering; penetrating a cave further than 1/3 of your air supply allows is simply foolhardy. Don’t give in to urges to explore beyond that mark, no matter how experienced a diver you are.
Special Equipment
If you plan to become certified to cave dive, you will need to invest in a little more equipment than you may already have, depending on where you plan to dive and how deeply you plan to penetrate caves and caverns. Double cylinders are a must, and so are warmer wetsuits or dry suits. In addition, cave divers wear special harnesses with aluminum or stainless steel back plates, a BC with a shorter inflation hose than found on recreational BC’s and without a shoulder dump valve. In addition, cave diving harnesses have extra D-Rings for stages and other equipment. Very strong wrist mounted lights with waist-mounted canisters are a necessity as well. Reels are a must, and split fins are a major no-no. Anything that presents a snag or drag hazard is stored differently or done away with; for example, cave divers don’t use snorkels.
The importance of proper cave diving training cannot be stressed enough; without it, you may as well sign your own death certificate. The majority of cave diving deaths occur when improperly or inadequately trained divers push boundaries; but with an investment in the right level of training and proper equipment, plus sound practices firmly based in reality, you can experience some of the world’s most exciting cave dives and live to tell the tale.