CCR Cave Diver Upgrade

Course overview

  • Cave Training: CCR Cave Diver Crossover

  • Price per day: $300 USD.

  • Minimum training days: 3 – 6 days.

  • Duration: 600 minutes of bottom time.

General Requirements & Conditions

Minimum Age: 18
Physical Condition: High
Entry level: Advanced Open Water + Nitrox
Water Temperature 21°
Air Temperature 35°

Course Standards


The NSS-CDS CCR Cave Diver course is the closed-circuit equivalent of the Apprentice and full Cave Diver courses combined.

Divers using a CCR in an overhead environment should adhere to rules and guidelines to execute dives in a safe manner and develop the skill set to deal with issues within the environment that may arise. This course is designed to develop the physical and mental discipline for cave diving on a CCR.

  1. In addition to meeting the normal prerequisites for NSS-CDS Apprentice Cave Diver training, students must hold Rebreather Diver certification from a widely recognized training organization and provide proof of a minimum of 25 logged dives and 35 hours bottom time using the same CCR as they will use during this course.
  2. Students participating in any training program involving planned decompression must possess appropriate certification from a widely recognized diver training organization.


This course is the third stage of training in the series of TDI’s Rebreather Cave Diver development program.

Advanced rebreather cave dive planning, the practical execution of different types of cave systems and scenarios divers encounter are presented. This rebreather cave diving course is not intended to prepare divers for evaluating all facets of cave diving. The objective of this course is to expand and critique previous skills accomplished in the TDI Rebreather Cavern Diver and Rebreather Intro to Cave programs. Emphasis is placed upon dive planning and skill perfection through actual cave penetration.

  1. Students must be have the TDI CCR Air Diluent Decompression Procedures Diver certification or equivalent.
  2. Provide proof of certification as a: TDI Rebreather Intro to Cave or TDI Full Cave Diver.
  3. Provide proof of a minimum of 50 logged dives and 50 hours on the rebreather unit used.
  1. Divers who are certified both as TDI Full Cave Diver or equivalent AND TDI Air Diluent CCR Decompression Procedures Diver or equivalent may be upgraded to TDI Rebreather Full Cave Diver by completion of all course requirements except:
    • Four cave dives are required with a minimum accumulated bottom time of 240 minutes at two different sites. At least two of the dives must be at least 75 minutes long.
    • All other course requirements must be met.
  1. Required in-water skills to focus on integrating the CCR into full cave diving including:
    a. Bailout planning
    b. Complex dive planning (hub and spoke diving).
    c. Complex navigation.
    d. Exiting the cave in SCR mode.
    e. Exiting the cave with simulated solenoid failure (if applicable).
    f. Exiting the cave on open circuit bailout.
    g. Demonstrate rebreather unit specific skills in compliance with current level of rebreather certification as outlined in the TDI course curriculum.

What’s included

  • Classroom sessions

  • Transport to and from the cenotes.

  • Air fills and tanks.

  • Certification card.

  • Weights.

Not included
  • CCR unit.

  • Training Manual.

  • Basic Diving Gear.

  • Nitrox or Helium Mixes.

  • Diving insurance.

Equipment Requirements

Each participant must have:

  • Mask and fins.

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

  • Sidemount/backmount harness and air cell with sufficient lift to support cylinders used.

  • Two sidemount cylinders or set of manifolded doubles capable of providing a starting gas volume of at least 4,200 L/150 ft3.

  • Two regulator first-stages, each with a single second stage. At least one first stage must have a 2.0 m/7.0 ft second-stage hose.

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

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

  • Primary dive light with a rated burn time of 150 percent of expect dive time and 2 backup dive lights.

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

  • Two safety reels/spools per diver, each with at least 30 m/100 ft of guideline.

  • At least two directional and two non-directional line markers.

Closed-Circuit Equipment Requirements

In lieu of sidemount/backmount cylinders and regulators, students and instructors using closed- rebreathers must have:

  • A CCR or eCCR with sufficient absorbent, diluent and oxygen for 150 percent of the planned dive time.

  • Open-circuit bailout cylinder(s) with at least 150 percent of the gas required to exit the cave from maximum point of penetration. This must be in the form of either two or more separate cylinders or a single cylinder with an H-valve.

  • Additionally, both students and instructors must hold CCR Diver certification for the specific CCR they will use.