History of the NSS-CDS

History of the NSS-CDS

The National Speleological Society-Cave Diving Section (NSS-CDS) is a 501(3)c non-profit corporation with a rich history in conservation, education, exploration and safety.  In fact, the roots of the organization run so deep that it is impossible to separate NSS-CDS history from the history of cave diving itself!

The NSS-CDS was started by cave diving members of the NSS (National Speleological Society, the largest dry caving organization in the world) in 1973.  The organization grew out of meetings in Missouri and Indiana in 1973 at the annual NSS convention.  Sheck Exley was the first chairman, and Volume #1, Issue #1 of the journal later became Underwater Speleology.   By 1976, the NSS-CDS was the largest cave diving organization in the world, a position that it has maintained continuously since that time.

Safety and Training

NSS-CDS training directors Forrest Wilson, Wes Skiles, and Joe Prosser developed a program of cave and cavern certification that has produced more qualified cave and cavern divers than all the other organizations combined.  The first group of crossover instructors was certified in 1979 and the first NSS-CDS instructor institute was held in Branford, FL in 1980.  Many of the educational materials that we still use today were developed by the 1980s.  Accident analysis results allowed identification of safety rules that greatly enhanced cave diving survival (published as Basic Cave Diving: Blueprint for Survival, Exley, 1979).  Other publications included the NSS Cave Diving Manual (Exley and Fuller, eds., 1982), the NSS-CDS Instructor’s Training Manual (Joe Prosser, ed, 1985, 1998), Basic Underwater Cave Surveying (John Burge, 1987), and the NSS Cavern Diving Manual (Zumrick, Prosser, and HV Grey, 1988).

Cave maps, created by the section’s explorers, were made available to members.  Cave diver search and recovery, headed by Henry Nicholson, was made part of the curriculum and Tampa diver Dustin Clesi wrote an NSS-CDS specialty course on DPV use in caves. By mid-1982, 115 divers had received the Abe Davis Safe Cave Diving Award. Just seven years after the first instructor institute, the CDS had awarded 6089 certifications, yet the number of fatalities continued to drop from the all-time high of 26 in 1974 to less than five per year. This is a tribute to the NSS-CDS educational efforts.

By the early 1990’s, NSS-CDS started a computer bulletin board to enable members to access to Underwater Speleology and shareware for nitrox and decompression.  The NSS-CDS Workbook was published in 2002, and the Spanish language version, Manuel Del Estudiante in 2007.   The NSS-CDS developed a rebreather cave diving certification and sidemount course materials.

Innovations and Improvements

Cave divers have been at the forefront of equipment improvement, and CDS divers have led the way.   NSS diver John Harper’s long explorations done in the 1960’s prompted him to use plastic jugs for buoyancy compensation, Sheck was the first to use tank staging during the Little River exploration and to survey caves accurately at Madison in 1970 and Woody Jasper and other explorers rigged their tanks on their sides when restrictions stopped their progress in back mount.  Frank Martz started manufacturing the first dependable, bright underwater lights and guideline reels and Jamie Stone, and Jim Lockwood modified the Farallon MK 7 DPV by replacing its lead acid batteries with NiCad ones to extend burn time and range.

Safety concerns dictated other innovations.  By 1968, Sheck Exley proposed the “Rule of Thirds” that we still use today.  Following Bill Hurst’s death at Peacock, Lewis Holtzendorff began using arrow-shaped duct tape markers, dubbed “Dorff markers”, on the line to point to the nearest exit.  These “Dorff markers” were used until Forrest Wilson developed the plastic line arrows that are widely used today.  Forrest also created the first “jam proof” reel in 1977; three years after Dana Turner introduced the “L handle” design.  The CDS also began to place “grim reaper” signs at the entrances to caves to warn untrained divers of the danger of entering a cave.

In 1987, Wes Skiles presented an article on the “Scientific Future of Cave Diving.” Topics included surveying, cartography, dye tracing, water chemistries, photography, and biological/geological sampling.  He emphasized the use of multiple staging and use of nitrox mixtures and discussed the new decompression habitats, which allowed divers to warm up, rehydrate, and eat in safety and relative comfort.


Early survey and mapping of Florida’s underwater caves marked the “golden age” of cave diving exploration.  During the 1960’s, NSS diver John Harper was the first American diver to regularly lead teams beyond the daylight zones.  He and Joe Fuller set records for the world’s first 1000 foot penetration in Hornsby Sink and doubled this distance for a world’s record first traverse distance in December, 1962.  John’s teams discovered most of the submerged passage explored in this decade.

The next ten years saw underwater cave passage expanded to approximately 200,000 feet and Sheck Exley was lucky enough to be the first to see most of this, together with dive partners Carl Fowler, Chuck Stevens, Charlie Sturdivant, Dutch Vande Noord, Court Smith, Lewis Holtzendorff, Dana Turner, David Fisk, Clark Pitcairn, Ken Hillier, Bob Goodman, Bill Walters, Dale Sweet, Mary Ellen Eckhoff, John Zumrick, and Paul DeLoach, among others. Florida’s Peacock Springs Cave System was the world’s longest known system at the end of the 1970’s, having been surveyed by NSS-CDS members to 20,293 feet.

Significant cave-diving exploration was also pursued by NSS divers in other parts of the U.S. in the 1970’s. The longest penetration in the U.S. outside Florida was 2200 feet, by Stephen Maegerlein at Hopper Spring, Indiana, though this was nearly equaled at the much deeper Roubidoux Spring, Missouri, by Frank Fogarty, Roger Miller, and Terry More. Cave diving was also used to connect dry caves, such as West Virginia’s My Cave to Simmons-Mingo by Barney Burdiss, Forrest Wilson, and others in February 1979.

The 1980’s saw cave exploration in Florida more than double, but it was no longer dominated by a relatively few divers.   Most of the prominent Florida cave explorers of the 1970’s were no longer active, though Paul DeLoach, Wes Skiles, Bill Main, Mary Ellen Eckhoff, John Zumrick, Clark Pitcairn, Paul Heinerth and Sheck Exley continued their efforts. They were joined in the early 1980’s by cave divers like Woody Jasper, Lamar Hires, Bill Gavin, Tom Morris, Mark Leonard, Paul Smith, and Lamar English to name a few, and in the latter half of the decade by Larry Green, Bill Stone, Tara Tanaka, and Parker Turner, to name a few more

NSS-CDS members Dennis Williams, Jill Yager, Gene Melton, and Mary Brooks explored and surveyed more than 30,000 feet of passage in Lucayan Caverns, Bahamas, surpassing Peacock as the world’s longest known underwater cave. Perhaps even more significant, Jill discovered an entirely new class of animal in the cave, which she named remipedia. By the end of the decade, Lucayan was exceeded once more by Florida’s gargantuan Cathedral/Falmouth System.

Many of the most difficult dives of the 1980’s did not involve records, Jamie Stone and Sheck Exley’s 1980 bottoming of Weeki Wachee Springs in the face of a so-called “impossible” current is one example and Woody Jasper, Tom Morris, Lamar Hires, Wes Skiles, and Paul Smith used British sidemount technology to squeeze through many “impossible” restrictions to make such exciting discoveries as the 7000-foot-plus linking of Telford Springs to Irvine Slough (Luraville Spring), another.

NSS-CDS cave divers began exploration of Yucatán’s underground rivers and cenotes. Sheck Exley began diving in Nacimiento del Rio Mante in the Sierra Madre Mountains of northern Mexico, and NSS-CDS member, Jim Coke and others, did the first surveys of Dos Ojos, Xel-Ha, Najaron and Mayan Blue cenotes.

IN 1996, The Northeast Sump Exploration Team (NEST) was founded by Joe Kaffl and became an official project of NSS in 1997.

NSS-CDS Properties:  The NSS-CDS maintains ownership or stewardship of the following properties:

1993 - Alachua Sink donated to NSS and a management plan drafted, allowing cave access.

1997 - Cow springs purchased by the NSS-CDS

2004 - School Sink Wayne’s World

The NSS-CDS Looks to the Future...

The dives of 1980 seemed impossible as we struggled to make the first 2000-foot penetrations in 1970 and Cave divers are now making penetrations of over five miles long and nearly 900 feet deep. It is reasonable to assume that this progress will continue as NSS-CDS members lead the way with new safety equipment and procedures. Rebreathers make possible continuous immersions of more than 48 hours, even at considerable depths, and work continues on ever safer decompression tables, improved scooters and minisubs to increase the range of cave divers as well.

Through continued education, aimed at the recreational diver, by the NSS-CDS and other concerned agencies, we expect the number of untrained diver deaths to continue to decrease.

It is not unreasonable to expect the amount of known cave passage in Florida to double again in the next decade, as well as the number of divers to continue to increase.  Cave conservation efforts will become increasingly important and one of the real challenges of the decade will be how to accomplish this. A larger still threat to the caves is the continued deterioration of water quality from pollution and water shortages due to increased population, industry, deforestation and ground-water-based irrigation.

While these problems are imposing, the NSS-CDS will continue to seek and support solutions to them. and NSS-CDS members will continue to be at the forefront of education and exploration of caves worldwide.

Please consider joining us, volunteering for the organization or one of its projects, or making a tax deductible contribution to the organization.

Additional links which may be of interest: