Rebreather Information & Specs

CCR- Closed Circuit Rebreathers

I have been diving rebreathers since 1996 and have logged several thousand hours on multiple units in a range of environments from deep wreck to caves in both tropical and cold water. This section of my website overviews some of the benefits Rebreathers bring to the sport diving community. I have selected specific units that meet the demands of the worlds Technical Diving community.

I personally own and dive these units to stay current with advancements and changes in design. Key consideration to my unit selection includes Manufacture support, Third party testing and configuration options.


The last decade has seen massive growth in the number of Rebreather units sold and used by sport divers around the world. This section of my site is aimed at educating divers on closed circuit technology.

A rebreather is SCUBA that allows you to re-breathe the exhaled gas you have already consumed, unlike open circuit scuba, you breathe directly from the cylinder and then vent all the gas into the surrounding atmosphere.

We only actually metabolise around 4% of the inspired oxygen, the balance is exhausted along with CO2. The rebreather captures the exhaled gas and re-uses it by removing the CO2 and re-circulating the oxygen, it also adds fresh gas to the system to keep it at a life sustaining level.

There are four different types of rebreather; SCR semi closed, CCR fully closed, Passive injection PSCR and oxygen rebreathers. The semi closed works on a principle of consistently adding fresh gas to the loop while re-using the exhaled gas. These units also vent a portion of the gas into the atmosphere, and even though this happens the gas supply lasts significantly longer than open circuit. A closed circuit rebreather is a fully closed unit that doesn't vent any gas and re-circulates all the gas, and rather than constantly adding gas the unit monitors the level of oxygen in the unit and only adds oxygen at the time the unit needs it to maintain the preset or desired partial pressure of oxygen PPO2. An oxygen rebreather works on the same principle as CCR but the use of pure oxygen limits their use to 6m in depth.

The added benefits of rebreather diving include; bubble free quieter diving making them great for underwater research and photography, moister warmer breathing providing great thermal benefits to diving in colder climate. For the technical diver Rebreather bring a world of advantages to deeper longer divers in optimal gas usage, constant PPO2 decompression, smooth gas transitions optimizing N2 & He spikes on ascent helping to avoid ICD issues.

Modern rebreathers are reliable and safe as long as the user fully understands the unit and its possible hazards. Each unit requires specific training and it is very important if you are considering diving with a rebreather that you seek training from an experienced rebreather instructor affiliated to a reputable rebreather centre.

Once you start diving on a rebreather you many find it very difficult to come back to the dark ages of open circuit diving.