NSS-CDS Training Program

Cave Diver

Cave Diver

Let’s start off by avoiding any confusion. The process of becoming a fully certified NSS-CDS Cave Diver used to involve four steps. Now it’s just two, as shown here:

Old vs new

The new process is more straightforward and results in better trained, better-prepared Cave Divers. Key points include:

  • Cavern Diver is no longer a prerequisite for Cave Diver training, nor does it count toward Cave Diver certification. Nevertheless, Cavern Diver remains a valuable program for many divers, including those unsure if cave diving is really for them. Learn more.
  • Students using open-circuit must do the entire course in complete cave diving equipment. This means either backmounted doubles or sidemount. No single cylinders…period.
  • Students must enter the course having prior training or equivalent experience in doubles or sidemount. For those who do not, we have the new CDS Basics orientation.

Although this is largely how many instructors have been teaching over the past few years, now it’s mandatory. As shown in the diagram, NSS-CDS Cave Diver training now consists of two steps. These are:

  • Apprentice Cave Diver
  • Cave Diver

Here is what you need to know about each:

Apprentice Cave Diver

  • The new NSS-CDS Apprentice Cave Diver course takes the place of the old Cavern, Basic and Intro-to-Cave Diver courses. The new course is more comprehensive, though, and asks more of students.
  • The Apprentice Cave Diver course focuses primarily on limited penetration along the main line. It is also where students learn and master critical emergency skills.
  • The Apprentice course further provides students with the opportunity to gain limited experience and practice fundamental cave diving skills prior to completing the requirements for full Cave Diver certification.

Cave Diver

This course builds on the knowledge, skills and experience students gain during the Apprentice Cave Diver course. In addition to ensuring students have maintained knowledge and skill proficiency from the Apprentice course, the Cave Diver course focuses on:

  • Cave navigation involving jumps and gaps and, at a minimum, the theory behind complex circuits and traverses (those requiring establishment of a halfway or “point of no return”).
  • How students can apply their open-water decompression training to caves.


  • Be at least 18
  • Possess a minimum of Nitrox and Advanced Open Water Diver certifications, or equivalent, from one or more widely recognized diver training organizations
  • Have logged at least 50 dives
  • Provide proof of certification in Technical Sidemount or some form of Basics/Fundamentals/Essentials from a widely recognized technical diver training organization, or provide proof of equivalent experience in sidemount or backmounted doubles.
  • Prior to or concurrently with the second part of the program (“full” Cave Diver), students must acquire training and certification in decompression procedures and the use of high-oxygen-content gas mixtures for decompression.

Additionally, instructors must screen and evaluate students to ensure they possess adequate buoyancy, trim and propulsion skills. If they do not, students may take part in the CDS Basics orientation to acquire the necessary skill levels.


The duration of the Apprentice and full Cave Diver courses together is:

  • Typically six or more days; generally broken down into two segments of at least four days each
  • At least 16 dives
  • At least 600 minutes of bottom time

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Course Standards

Form These are the standards instructors must follow when teaching this course. It includes information on student and instructor prerequisites, course content, skill requirements and limits of training.