Although most overhead environments are casually referred to as caves, many are actually caverns. There are some important distinctions between cave diving and cavern diving. Here, we explore the differences.
Defining Cave Diving and Cavern Diving
In cave diving, a cavern is defined as the portion of the cave which is penetrated by natural light from outside, while a cave is defined as the portion of the subterranean structure that receives no natural light from outside. Cavern divers and cave divers use many of the same strategies, however there is a distinction between cave diver and cavern diver certification.
Cavern divers typically go no further than 130 feet from the entrance and always keep it within their line of sight, while cave divers often penetrate much further into the structure. Both cave and cavern divers use guidelines to ensure that they are able to make it back to the entrance safely.
Cavern divers retain the ability to make emergency swimming ascents, and by definition, cavern diving is a form of recreational diving rather than a form of technical diving. Cavern divers receive specialty diver certifications from agencies such as PADI, NAUI, SSI, and SDI.
Cave divers receive their specialty certifications through cave diving associations such as the National Association for Cave Diving (NADC) and the National Speleological Society Cave Diving Section (NSS-CDS), or from technical diving organizations such as IANTD, TDI, GUE, and NAUI Tech.
Equipment for Cave and Cavern Diving
Because cavern diving comes with less inherent risk than cave diving, cavern divers are able to use much of the same equipment as is used in open water. Being in a cavern does require a few equipment changes, but these are minor and can make open water diving easier and even more enjoyable.
In contrast, cave divers must use highly specialized equipment to mitigate the risks they encounter as an inherent part of cave diving. Perhaps the most noticeable example is the gas delivery system; a cavern diver uses a single tank equipped with K-valves and a single regulator first stage. Whether using single or double tanks, cave divers always use systems in which a single breathing gas supply feeds two separate on and off valves and two regulator first stages. This vital safety configuration is used in the event a valve to regulator O-ring ruptures, or a regulator goes into free flow, the malfunctioning valve/regulator combination can be shut off and egress can occur using the remaining valve and regulator.
Because cavern diving has modest risks associated and is considered a form of recreational diving, it is a specialty that just about any experienced diver will find fun to learn and take part in. Cave diving, on the other hand, is inherently risky and is a far more specialized pursuit. It is not for everyone: Successful cave divers are skilled divers who have a commitment to discipline.
Safety is key to both cave and cavern diving, as is appropriate equipment and the right mindset. Both, when performed correctly, offer rewarding adventures to those who enjoy the adrenaline rush that comes with exploring new and exciting places.