TDI Helitrox CCR


This is the second level certification course for divers wishing to utilize a Closed Circuit Rebreather (CCR) for mixed gas diving using a Helitrox Diluent. The objective of the course is to train divers in the benefits, hazards and proper procedures for diving a CCR and to develop basic CCR diving skills, to a maximum of 45 metres/150 feet, using an air/nitrox/helium diluent for formal decompression diving. Students are permitted to utilize a diluent and bailout mix with no greater than a 35% helium content and no less than a 21% oxygen content, and are permitted to use up to 100% oxygen for decompression.

Who this course is for:

  • The certified TDI Air Diluent Diver (or equivalent) who is looking to extend their depth limitations, learn CCR decompression procedures, and reduce narcosis
  • The open circuit TDI Advanced Nitrox and Decompression Procedures or Helitrox Diver looking to utilize CCR technology to extend their depth limits and bottom times

Course Duration:

Courses should not be treated as a race or something that can be skipped through quickly. Please remember training does not guarantee certification, we need to ensure you fully understand the training and will be a safe diver on certification. We follow a loved one clause that when certified we would be happy you could safely dive with one of our loved ones.

We will strive to meet your timelines and requirements where possible and will always be dependant on student availability to attend sessions.


Course prerequisites & forms:

  • Minimum age 18
  • Proof of 50 logged dives
  • Minimum certification level of TDI Advanced Nitrox Diver, Deco Procedures Diver or Helitrox diver or equivalent from agencies recognized by TDI
  • If the rebreather is a TDI approved sidemount rebreather, the student must hold the TDI Sidemount Diver Certification or equivalent and provide proof of 10 logged sidemount dives 

Medical Form
Liability Release 

What you can expect to learn:

The TDI Diving Rebreathers Student Manual and the manufacturer’s manual are mandatory for use during this course but instructors may use any additional text or materials that they feel help present these topics. The following topics must be covered during the course:
    • History and evolution of rebreathers
    • Comparison of open circuit, closed circuit and semi closed circuit rebreather systems and the benefits/problems with each
    • Practical mechanics of the system
      • Assembly and disassembly of the unit
      • Layout and design of the unit
      • Absorbent canister design and maintenance
      • Proper packing of canister, in accordance with manufactures recommendations
      • Breathing loop de-contamination procedures
      • Manufacturer supported additional items (automatic diluent valve, etc.)
    • Gas physiology
      • Oxygen toxicity
      • Nitrogen absorption
      • CO2 toxicity
      • Gas consumption
    • Electronic and manual systems design and maintenance
      • O2 metabolizing calculations
      • Fuel cells
        • Maintenance
        • Replacement
        • Manufacturing date
      • System electronics functionality and calibration procedures
    • Dive tables
      • Constant partial pressure of oxygen (PPO2) theory
      • Central nervous system (CNS) and awareness of oxygen tracking units (OTU)
    • Dive computers
      • Mix ajustable
      • Constant PO2
      • O2 integrated
    • Dive planning
      • Operational planning
      • Gas requirements including bailout scenarios
      • Oxygen limitations
      • Nitrogen limitations
    • Emergency procedures
      • Use of B.A.D.D.A.S.S.
      • Three H’s problems
      • Flooded loop
      • Cell warnings
      • Battery warnings
      • Bailout gas requirements
    • Helium considerations
      • Helium absorption and elimination
      • Advantages of hyperoxic mixes for decompression
      • Advantages of helium for bottom gas
      • Hypoxia
      • HPNS
      • Effects on respiration
      • Effects as an insulator
      • Helium limitations

    What’s in it for you?

    Upon successful completion of this course, graduates may engage in decompression diving activities utilizing a CCR without direct supervision provided:
      • The diving activities approximate those of training
      • The areas of activities approximate those of training
      • Environmental conditions approximate those of training
      Upon successful completion of this course, graduates are qualified to enroll in:
        • TDI Mixed Gas CCR unit specific course
        • TDI Advanced Wreck Course

        How to take this course?

        • Get in touch with us by phone, whatsapp, facebook or e-mail

        Price & Value:

        TDI Helitrox CCR - Please Enquire

        *Fully inclusive of all e-learning, training and certification on successful completion. Gas costs are separate and instructors Gas bill must be covered by students.

        We focus on and are proud of the skill level, knowledge, decision making, experience and readiness of divers to dive at levels which they have been trained. We want to invest in you, your safety and ability to dive, then come home with amazing stories.

        Our courses are priced as such and we do not hide additional costs. We are are very flexible for training, especially in terms of dates or location as we know we all have busy lives and work commitments. However if for reasons outside of weather, illness or other such emergencies a course/training can not be completed in the standard training schedule we will charge for extra days at €150,00 per day.