Cavern Diver

Course overview

  • Cave Training NSS CDS – Cavern Diver

  • Price per day: $270 USD.

  • Minimum training days: 3.

  • 4 Dives.

The NSS-CDS Cavern Diver course is a safety and awareness course aimed at open-water sport divers. It is not a prerequisite for, nor does it count toward Cave Diver training and certification.

Students in the Cavern Diver course use standard, single-tank sport diving equipment. They are not allowed to use sidemount, backmounted doubles or CCRs.

Requirements & Conditions

Minimum Age: 18 years old
No. of Dives Logged: 25
Physical Condition
Entry Level: Advanced OW + Nitrox
Water Temperature 21°
Air Temperature 35°

The Cavern Diver course helps or allows students to:

  • Avoid the mistakes which lead to cave-diving fatalities.

  • Educate fellow divers about the risks and hazards inherent in cavern and cave diving.

  • Improve critical diving skills such as buoyancy.

  • Better dive as a team with similarly trained buddies.

  • Use dive lights in state parks and other sites where such use is limited to certified Cavern and Cave Divers.

  • Safely dive in overhead environments while remaining within clear sight of the entrance and daylight.

  • Improve the functionality of their single-tank, sports diving gear.

Cavern Diver students will be better equipped to assess whether they possess the skills needed for Cave Diver training. They can also better evaluate whether it is worth the time and expense to do so. Students must possess Advanced Open Water Diver and entry-level Nitrox Diver or equivalent certifications from a widely recognized diver training organization, or equivalent experience. This training may take place concurrently with the CDS Basics orientation or Apprentice Cave.

Students participating in any training program involving planned decompression must possess appropriate certification from a widely recognized diver training organization. This training must cover:  Use of pure oxygen or oxygen-rich decompression mixtures and procedures for decompression diving. This training may take place concurrently with NSS-CDS Cave Diver training.

Additionally, instructors must screen and evaluate students to ensure they possess the necessary attitude, knowledge and skills before any further in-water training takes place. Instructors must refer students who cannot pass this screening process to opportunities where they can obtain remedial training. Only when students can pass the screening process may they continue their cavern/cave training.

  • Classroom sessions

  • Transport to and from the cenotes.

  • Speciality equipment.

  • Air fills and tanks.

  • Certification card.

  • Weights.

Not included
  • Training Manual.

  • Basic Diving Gear.

  • Nitrox or Helium Mixes.

  • Diving insurance.

Equipment Requirements

Equipment requirements for the Cavern Diver course are similar to those for other NSS-CDS courses. The chief difference is cavern diving equipment is based on single-tank, open-water gear. Students must have:

  • Mask and fins.

  • Single-Tank BC.

  • Adequate exposure protection for depth, time and water temperature.

  • Single cylinders capable of providing a starting gas volume of at least 1,850 L/65ft3.

  • Regulator system with primary and backup second stages. The primary second stage must have a 1.5 m/5.0 ft or longer hose.

  • At least one dive computer capable of monitoring exposure to all gas mixtures used.

  • At least one cutting tool capable of dealing with guideline entanglement.

  • Primary dive light with a rated burn time of 150 percent of expect dive time and 1 backup dive lights.

  • One primary reel per team with minimum of 75 m/250 ft of guideline.

  • One safety reel/spool per diver, each with at least 30 m/100 ft of guideline.



The CDS Training Program is the teaching arm of the National Speleological Society Cave Diving Section. The NSS-CDS is a subset or Section of the NSS. It focuses solely on underwater cave exploration. It offers a wide variety of cave diving courses and cave diver learning opportunities. We have instructors in the Bahamas, Mexico, Russia, the USA and throughout western Europe. We train and certify hundreds of cave divers annually. Although relatively small in size, NSS-CDS instructors have had a profound impact on how people dive and teach around the globe. We were pioneers in:

  • Using backplates, harnesses and wings for doubles.
  • Using modern sidemount equipment.
  • Standardized cave diver training.
  • Teaching entry-level scuba students to perform skills while neutrally buoyant.

Most of the larger technical and sport diver training organizations pattern their Cavern and Cave Diver programs after what we teach. Many of their headquarters staff have taken courses from us. It would be fair to say we’ve actually changed the way the world learns to dive…for the better.

The National Speleological Society-Cave Diving Section (NSS-CDS) is a 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.

The Program

The primary purposes of the Cave Diving Section of the National Speleological Society (NSS- CDS) are to educate the general public in the proper procedures and techniques for participating in cavern or cave diving while simultaneously protecting the cave(rn)s from harm. Formal training stresses the importance of cave conservation in addition to safe diving practices and procedures.

The NSS-CDS is committed to the safe and proper enjoyment of the cave environment. The NSS-CDS believes that with proper training and guided experiences one can visit underwater caves in a safe manner. Further, we believe that a properly trained cave diver will significantly reduce the damage that can be caused to the cave environment and its unique features.

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.

The goals of the NSS-CDS Training Program

Establish and maintain standards and procedures for the training of scuba divers in cavern and cave diving. Establish and maintain standards and procedures for the development of cavern and cave diving instructors. Develop and make available outlines and other educational support materials for cavern and cave diving training. The National Speleological Society believes that: caves have unique scientific, recreational and scenic value; these values are endangered by both carelessness and intentional vandalism; these values, once gone, cannot be recovered and the responsibility for protecting caves must be assumed by those who study and enjoy them. Accordingly, the intention of the Society is to work for the preservation of caves with a realistic policy supported by effective programs for the encouragement of self-discipline among cavers, education and research concerning the cause and prevention of cave damage and special projects, including cooperation with other groups similarly dedicated to the conservation of natural areas.