SCR (Semi-Closed Circuit) and CCR (Closed Circuit) Rebreather Systems

ccrRebreather diving is underwater diving using rebreathers, which re-circulate the breathing gas (air or Nitrox/Trimix) already used by the diver after replacing oxygen used by the diver and removing the carbon dioxide metabolic product.

The primary advantage is extended depths and bottom times, with many units offering fixed *PPO2 options.

(*Partial Pressure of Oxygen) reducing risks of O2 toxicity on deeper dives.

dirkSCR Vs CCR What is the difference?

The closed circuit rebreather will add the exact amount of oxygen needed and will be more efficient and quieter than the semi-closed system.

scrSemi-Closed Circuit Rebreathers (SCR) only use one gas cylinder with an enriched air content. It usually pushes gas into the loop with a constant flow.

SCR is a great way to begin diving with a rebreather as it offers a relatively low-cost entry into technical rebreather diving.ap_diving

CCR is a natural progression from SCR or maybe entered into directly for experienced technical divers or experienced Scuba divers who have want to enjoy the benefits of CCR diving.

The major difference between SCR and CCR is that with SCR, it is a little less technical and very simple to operate with some expired gas being expelled into the surrounding water with every 4th or 5th breath or so... And CCR is more technical and more training is required also, more expensive to buy! The CCR does NOT vent expired gas and is therefore mostly SILENT and gets you closer to marine life in general... Popular for photography and UW Video work for this reason. 

ITDA Highly recommends AP Diving - Rebreathers..

CCR Benefits

  • Dive Deeper - the optimum nitrox mix at every depth
  • Stay Longer - with dramatically increased No-Deco bottom times
  • Greatly Reduced Deco - if you do incur penalties, O2 rich Deco gets you out of the water quicker
  • Extreme Low Gas Use - consumption is governed by metabolism not depth, so average use is only about 1 litre/min!
  • Greater Comfort - with warm, moist breathing gas
  • Versatility - out-of-the-box unit ready to go, shallow or deep
  • No Expensive Gas-mixing or Pre-planning - for a target depth
  • Perfect Buoyancy Control - unaffected by breathing
  • No Bubbles, Silent Diving - get up really close to the wild-life


submatixWhat does ITDA Offer?


ITDA offers both SCR (Dolphin Drager and Others) as International certification programs from our technical professionals and our technical training facilities around the World.  We also offer training and certification with CCR Rebreather units from AP Diving (Evolution and Inspiration) also, the SUBMATIX units from Germany. (pic. left.)

Our courses begin with a foundation generic theory course in "Rebreather Diving" and then we move on to unit specific programs many of which are "Manufacturer Approved" such as our AP Diving units. (Units and Instructors and divers MUST be registered with us and we pass and share this information with AP Diving.

ITDA SCR / CCR Course Programs:

  • Foundation in Rebreather Diving
  • SCR Rebrether Diver 30m/100ft.
  • SCR Advanced Diver
  • SCR Instructor
  • CCR Diver to 40m/132ft.
  • CCR Advanced Diver
  • CCR Mixed Gas to 100m/330ft.


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ITDA Group International Inc. Ltd.
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ITDA and IHMP, training scuba diving, advanced and technical, training professional divers, from diver to instructor, plus IHMP first-aid and IHMP instructor, plus, our unique divepro opportunity. 

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