TDI Rebreather Air Diluent (No DECO - 30mtrs)

No doubt if you are considering this course, you have already done some research on closed circuit rebreathers, and maybe even had a go! The reasons for taking this step are many and varied, but whatever it is that has motivated you to do so, this is the entry level rebreather course that will take you safely into the world of silent diving! At present, courses are only available on any of the Ambient Pressure Diving series of rebreathers (Classic, Evolution, Evolution Plus, and Vision) although future units will hopefully include the X-CCR, SF2 and JJCCR. Units are available for use for the duration of the course, or we are an authorised dealer for AP Diving and can advise you on and then arrange the purchase of a new unit.

Why TDI Rebreather Air Diluent (No DECO - 30mtrs)?

This is the entry level certification course for divers wishing to utilize an Ambient Pressure Diving closed circuit rebreather (CCR) for air diving. 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 depth of 30 metres / 100 feet, using air as a diluent. No decompression diving is allowed on this course.

Upcoming Courses (back to top)

No courses organised at the moment, please contact us to discuss your requirements.

How do I book myself on a course?

To book yourself on a course please select one of the courses above, send us a message, and we will get back to you to discuss further details.

Course Comments...

Below are comments from previous customers who have taken this course. If you have taken this course with us within the past six months please feel free to post your comments.

"After recently completing my Mod1 Rebreather course I thought I'd give you my thoughts.

My instructor for the course was Ian Mills, a guy I have known and whose opinion I have respected for some time. His knowledge concerning this topic appears all encompassing, something that I found to be very reassuring bearing in mind that, even as an instructor, I am stepping into the unknown again as a novice. His attention to detail and safety leaves nothing to chance, as it should be when electronics and water are interacting.

With regard to the course itself. The theory I found to be a mixture of basic diving practise and common sense, coupled with various new and interesting concepts that begin to lead you down the rebreather road. Underwater it is a very different feeling in terms of buoyancy and overall control, something that needs a lot of patience and a load of self restraint in terms of being self critical. Although the various gauges, handsets, stages, hoses etc etc make for a far more complicated method of diving, it is also extremely satisfying when you realise that you are able to achieve what you want with this unit. There are a whole load of new skills to learn that are rebreather dedicated and that will test your nerve and patience.

Overall I would say that if you enjoy a challenge and the thought of being tested, Ian will test you, then this is definitely for you. However, in my opinion, before trying this you need to have a real grasp of general diving practise and get many hours under your belt on a regular set up and have experience of different diving situations. This would not only be invaluable underwater but also on the theory side.

I must also say a big thank you to a good friend, Mark, for his constant support and encouragement, also for acting as my safety, (cameraman), in the water.

thanks both"

From John Lock, course taken April 2014

See more comments about this course....

Further information on TDI Rebreather Air Diluent (No DECO - 30mtrs) (back to top)

What do I need to start?

  • TDI Diving Rebreathers Manual 
  • AP Valves unit specific instruction manual (available to download from 
  •  TDI CCR Preflight Checklist

What will I do?

The course consists of a minimum of eight hours of theory/knowledge development, accompanied by a minimum of seven open water dives totalling 420 minutes dive time. There will be a gradual increase in depth of the dives over the five days to a maximum of 30 metres. 2 dives will be deeper than 20 metres, and one will be deeper than 27 metres.


Theory covered includes:


  • History of Rebreathers 
  • Comparison of OC, SCR and CCR 
  • Practical mechanics of CCR 
  • Gas physiology 
  • Scrubber packing 
  • O2 addition systems 
  • Dive tables/computers/planning 
  • Emergency proceedures 


Dive skills covered include:


  • Unit assembly 
  • Pre-dive planning 
  • Emergency procedures 
  • Loop volume control 
  • PO2 monitoring 
  • Buoyancy control 
  • Use of SMB 
  • Safety stops 
  • Post dive care/maintenance


How long will it take?

The course requires five days to cover all required material. The courses are usually scheduled to run over five consecutive days (Wednesday-Sunday). Other scheduling options are available (i.e. over two weekends) but we strongly recommend the course is completed over the shortest period possible. The course must be completed within a six week period. Please understand that the course is performance based. This means that certification is only awarded upon demonstration of being capable to conduct rebreather dives. This may involve further training dives beyond the seven required. While not required reading, the following books/articles are recommended reading prior to the course:
  • Richard Pyle - A Learners Guide to Closed Circuit Rebreather Operations 
  • Kenneth Donald - Oxygen & the Diver 
  • John Lamb - Oxygen Measurement for Divers 
  • Barsky, Thurlow & Ward - The Simple Guide to Rebreather Diving 
  • Bob Cole - Rebreather Diving 
  • Jeffrey Bozanic - Mastering Rebreathers

What previous experience do I need?

To enrol on this course students must:


1. Be minimum age 18

2. Provide proof of 20 logged open water dives

3. Provide proof as a TDI Nitrox Diver or equivalent.

What do the fees include?

  • All professional tuition 
  • Insurance costs while on the course 
  • TDI Course manual 
  • Use of oxygen analyser
  • Use of a Rebreather
  • 3 fills of sofnalime (enough to complete the course in specifie time)
  • Diluent
  • TDI certificate upon completion
  • TDI registration upon completion

What don't fees include?

  • Entry fee to dive site/boat used for the Open Water dives (if applicable) 
  • Costs of transportation to and from dive sites (if applicable) 
  • Any personal costs (eg. food, drink, accommodation) 
  • Oxygen gas fills 

What can I do once I'm qualified?

Upon successful completion of this course, graduates may: Engage in diving activities utilizing the CCR to a maximum depth of 30 metres / 100 feet, utilizing air as a diluent.

What's next?

Upon completion of this course, students are able to progress to the next level of rebreather certification: TDI Air Diluent CCR Decompression Procedures Diver. If student does not hold TDI Advanced Nitrox and Decompression Procedures Certification (or equivalent) then this next level of rebreather certification can only be earned after the student has 30 hours experience on the unit.