CCR Liberty FAQ

Common

What are the main advantages of the Liberty rebreather?

The Liberty rebreather presents a unique system that has been designed to be fully fault tolerant, meaning that the system has built in electronic redundancies. Our primary concern was to build a rebreather system that will enable the diver to safely conduct the dive and will be able to return on the unit.

No single malfunction in the electronic system can cause a complete system failure.

Unit contains: 4 oxygen sensors, 2 helium sensors, 2 methods of pO2 measuring, 2 independent computers, 2 solenoid valves, 4 displays. Everything is individually sealed.

The Liberty rebreather is depth limited at 170m (557ft) due to the use of the Apeks DST4 Environmentally sealed 1st stage regulators. It is recommended that to dive beyond 170M (557ft) the Apeks DST4 1st stages MUST be changed with the Apeks UST4 kit. All components of the Liberty apart from the 1st stages are pressure tested to 600m. In conjunction with the Liberty robust construction the unit also exhibits one of the industry’s best work-of-breathing of rebreathers.

The Liberty rebreather has many variations you can choose and configure. The unit can be easily configured for multiple variations; backmount or sidemount, for optimal dive configurations for each dive environment. With a simple conversion kit the user can go from a backmount configuration to a sidemount configuration.

Watch our introducing video about Liberty rebreather and its advantages here.

Work of breathing?

Thanks to the careful design of all parts of the breathing loop, the Liberty has extraordinarily low breathing resistance. No off-the-shelf pipe fittings or piping components are used in the Liberty – everything is specially manufactured precisely according to calculations, simulations and test results. Please read our brief articles click here. The Liberty FMCL WOB is 2.16 J/l at 40m, air diluent. And 1.58 J/l at 100m, heliox 10/90.

Why two computers?

Having two computers provides redundancy in the unlikely scenario should there be a failure in one computer, the other computer will be able to completely maintain your decompression schedule and maintain proper PO2 measurement. Other rebreather platforms contain a single computer to which if there was any failure the system will be unable to manage decompression as well as drive solenoids to maintain proper PO2 thus bail-out is necessary.

Click here for control systems article.

Isn’t Liberty a technical overkill?

What Divesoft has done with the Liberty is to design a system from the bottom up to properly engineer a rebreather to sufficiently accommodate the requirements to avoid a single component failure. Technical diving demands redundancy and backups. Previously designed rebreather platforms where unable to avoid single part failures either with gas injection with a single solenoid, or single point PO2 monitoring with using only Oxygen cells.

Technical diving with closed circuit rebreathers can be a strenuous activity but without proper equipment, it can be a dangerous sport. The Liberty rebreather is designed to be fault-tolerant, which means that no single malfunction in the electronic system can cause a catastrophic failure of the whole system rendering the unit to be un-useable.

For more information click here.

Where and by whom is it built?

The Liberty rebreather is manufactured by Liberty systems, a sister company of Divesoft. The Liberty is built in our state-of-the-art facility in Roudnice nad Labem which is located in the northern part of the Czech Republic, just a few kilometers north of Prague.

Click here for a quick video of our factory.

What FW/Software/Algorithm is Liberty using?

We wrote our own software. We are using our own electronics as well. We are using upgraded Bühlmann ZHL-16B algorithm with gradient factors and ceilings. All is built and set in our own, state-of-the-art factory in the Czech Republic.

We are still growing, and so does the software of Liberty. FW updates are free of charge and you can easily read description of these changes on release notes or download new firmware version here.

What algorithm is Liberty using?

Bühlmann 16-ZHL/b with gradient factor and ceilings.

Can I connect my Shearwater?

No, in order to properly protect the electronics, the two main computers are environmentally sealed, preventing any hook up of external computers such as a Shearwater. Although, non-connected external computers are encouraged to be used as a secondary fixed PPO2 monitoring device.

Is there any literature referring to Liberty?

You can see our manual, YouTube channel, Facebook, Configurator or read references from professional divers.

What about some videos I can check out?

We have a YouTube channel where users can find videos about diving, tutorials, maintenance and much more.. Please click here.

Purchase & training

I am small/tall, will the unit fit me?

We have 4 different types of stands, three backplates, three different wings, three unit set-ups that we can configure for each individual diver in order to find the best way to fit the Liberty to you. You can size yourself to a unit with one of your local instructors during a DEMO event or get in touch with us directly.

Do you have Backmounted configuration?

Yes, the backmounted configuration was the original setup for the Liberty rebreather. You can configure your unit from sidemount to backmount per our website configuration here.

You can also configure the counterlungs for your unit from frontmount to backmount please go onto our website and use our configurator click here.

What agencies is the Liberty rebreather incorporated with?

  • ANDI
  • ASTD
  • BSAC
  • IANTD
  • IART
  • PSAI
  • RAID
  • TDI

Where and how can I find my instructor?

List of instructors is here.

Can I DEMO the unit before I decide to buy?

Yes, you can. Please contact us or our instructors.

What does the course typically cost?

Trainings and price of units are under the direction of our instructors.

We offer exclusive training under the guidance of our Factory Trainer Jakub Šimánek. Please contact us for Factory training price list.

What levels of training do you offer?

This is question for each instructor separately. Do not hesitate to contact them with your request. From the factory; we offer CCR Diver course, Liberty Crossover, CCR Diver Crossover, CCR Instructor, Liberty Instructor Crossover, CCR Instructor Crossover, CCR Normomix Trimix, CCR Full Trimix Diver, CCR Normomix Trimimx Instructor, CCR Full Trimix Instructor.

What am I getting for the price of the course?

CCR Diver Level – Class time requirements minimum of 12 academic hours and total dives of 8 dives over the course of 4 days.

Training agencies work with us to set the minimum standards to be met for the basic level CCR diver course, though instructors are always encouraged to teach beyond the minimum standards.

Do you offer any technician courses?

We offer Liberty technician courses. This course allows them to provide authorized service of Liberty rebreathers.

I want to see the factory, is it possible?

Factory visits are welcomed! If you are interested in visiting our factory we can offer you a tour by one of our sales representative, free of charge. At our factory we produce, design, and service all Liberty and Divesoft products as well as research and development!

Do you attend trade shows or events?

Yes, a variety of events and trade shows. Often we post our schedule to our social media sites.

Follow us on Facebook and Instagram for an updated list of dive events we attend!

UNIT Configuration

I am small/tall, will the unit fit me?

We have 4 different types of stands, three backplates, three different wings, three unit set-ups that we can configure for each individual diver in order to find the best way to fit the Liberty to you. You can size yourself to a unit with one of your local instructors during a DEMO event or get in touch with us directly.

Do you have Backmounted configuration?

Yes, the backmounted configuration was the original setup for the Liberty rebreather. You can configure your unit from sidemount to backmount per our website configuration here.

You can also configure the counterlungs for your unit from frontmount to backmount please go onto our website and use our configurator click here.

Do you have Sidemount configuration?

Yes, we offer sidemount configuration, or if you already own a backmount Liberty than see our conversion kit. You can configure your unit from sidemount to backmount per our website configuration here.

You can also configure the counterlungs for your unit from frontmount to backmount please go onto our website and use our configurator click here.

What is conversion kit?

If you already have backmount Liberty and wish to configure to Liberty sidemount, you can easily order a stand-alone conversion kit, which is significantly cheaper. The conversion kit is not a stand-alone rebreather. It does not contain Head, handsets, buddy and HUD.

Are the computers, tanks and cells included or do I have to buy them separately?

Everything is included ready to dive pending gas fills for tanks and sorb material for the scrubber.

Technical

What’s the weight of the Backmount unit?

BMCLFMCL
Unit only21.4kg (47.2lb)22.3kg (49.2lb)
With tanks32.5kg (71.7lb)33.4kg (73.6lb)
Titan18.5kg (40.8lb)19.6kg (43.2lb)
Titan + Tanks29.6kg (65.3lb)30.7kg (67.7lb)

All weights are without 2.5kg of sorbent and with empty cylinders.

For more informations about weight, dimension and other parameters of CCR Liberty backmount see Technical > Dimensions and performance.

What’s the weight of Sidemount unit?

scrubbershortstandard
Without sorbent and tanks12.9kg (28.4lb)13.8kg (30.4lb)
Without sorbent, EUR tanks (empty)19.2kg (42.3lb)20.2kg (44.5lb)
Ready to dive22.8kg (50.3lb)23.7kg (52.2lb)

For more informations about weight, dimension and other parameters of CCR Liberty sidemount see Technical - Dimensions and performance.

What materials are the Liberty rebreathers build of?

Stand and backplatestainless steel or titanium
Head and scrubberdelrin, aluminium,stainless steel
Wingscorduran
Counterlungspolyurethane
ElbowsEPDM rubber
Tankssteel
Valvessupplied by Nautec
First stage regulatorsupplied by Apeks

What kind of O2 sensors are you using?

Oxygen sensor 22D with a membrane. For more informations see: Fault-tolerant rebreather > 4 oxygen sensors.

Why helium sensors?

We implemented our unique helium sensors, that are also used in our analyzers, to measure the helium concentration with the utmost precision. With the advantage of an unlimited lifespan. For more informations see: Fault-tolerant rebreather > 2 helium sensors patented technology.

How many sensors in total?

The Liberty rebreather Head contains 4 oxygen sensors and 2 helium sensors.

How many computers does the Liberty have and where are they placed?

The Liberty has two independent computers and two wrist displays. The two main computers are located in an environmentally sealed compartment located in the head of the unit.

To see the exact description with graphic preview: Fault tolerant rebreather > 2 independent computers.

Please see our YouTube video describing the entire head anatomy here. Also, be sure to check out our YouTube page where we have many videos and descriptions of our equipment!

Can I use oxygen sensors sold by third party?

No, oxygen sensors made by AI (Analytical Industries) are not currently approved for the unit. Please note that it has to be type 22D with membrane.

What is plug and play system?

The Liberty rebreather has been engineered to be fault-tolerant, which means that no single malfunction in the electronic system can cause a breakdown of the whole apparatus. E.g. if your handset is flooded, you do not have to send to service whole rebreather. You just remove the handset from Liberty Head and send only the handset to service.

How hard is it to disassemble/assemble the unit?

When following our manufacturer assembly checklist during your initial training you will efficiently assemble and disassemble your unit.

The entire procedure is in our manual (page 52 – 53).

Maintenance tips

Is the unit self-maintenance one?

Some basic operations for every CCR diver are described in our Manual (pp. 74 – 77).

CCR Liberty requires annual service inspection performed by authorized service technicians or directly at our facility.

Please read our technical article by clicking here.

How often should the rebreather be serviced?

Maximum is after 13 months or after 150 hours of usage. Specialized service is recommended after 3 years (extra service: replacement of both battery packs and replacement of less exposed O-rings) and in 5 years (extra service: replacement of all hoses regardless of their condition).

What is the cost of the annual service?

Prices are determined by the Liberty authorized technicians. Please contact us and we will send you their contact information.

For more information please visit: https://www.divesoft.com/en/support/ccr-liberty-rebreather/service-operations

Can I service the unit myself?

It is important to understand that the Liberty rebreather is a life support machine that can be a technically demanding and sophisticated system. Any small mistake can lead to dangerous consequences that may endanger your health. Just like diving beyond training please refer to technical experts to service your life support equipment. If you wish to service your unit please look into our Technician training.

O-rings? What are they? How should I treat them?

O-rings are an industry standard for sealing tools in the SCUBA diving world. The efficiency lies in the elastic and water-resistant material. Since rebreathers use Oxygen it is crucial to always use Oxygen compatible lubricants and O-rings for any use with rebreathers in order to prevent Oxygen fires. This critical component will be covered in your introductory rebreather course and in your advance Nitrox class.

For answers to where they are and how to find it, watch our tutorial video here.

Do I need to use the O2 sensors you sell?

No but we recommend our O2 sensors as we specifically test them. Please note that it has to be type 22D with membrane.

You buy your Liberty rebreather where O2 sensors are also sold. Please take into consideration that all our oxygen sensors are tested at our facility, so you can be 100% sure of their function. Duration of O2 sensors is 1 – 2 years. After expiration you can buy O2 sensors wherever you want.

How can I install the O2 sensors correctly? How should I store them?

For installing oxygen sensors into Liberty Head watch tutorial our video here.

If you decide not to use oxygen sensor immediately after purchase. We recommend storing in unopened packaging in a refrigerator, to properly preserve sensor shelf life.

How to correctly disassemble the unit to let it dry out?

First, it will be necessary to dry out the water trap after each dive or by the end of the diving day. Begin by detaching the head, then remove the scrubber cartridge, next remove the water trap and dry it with a paper towel. With another paper towel, also dry the exterior surface of the cartridge.

The head should be left open in order to properly dry and to remove any excess moisture that may have formed on the oxygen and helium sensors. In areas with high humidity, we strongly recommend using the optional DIVESOFT Head drying fan. This ensures the functionality of both types of sensors.

Why is it necessary to use the drying fan?

However, the drying fan is only recommended. We find that the Divesoft drying fan can be very effective in removing moisture buildup that can occur on the oxygen sensors during a dive. Removing moisture can significantly reduce any error readings that may occur with a moisture buildup and help preserve the lifespan of the sensor.

How to store the unit between dive trips?

It is crucial to always properly clean your unit. When in use, the rebreather’s breathing loop can become a breeding ground for microorganisms from the diver’s respiratory tract and from the external environment. Following proper cleaning procedures can prevent the growth of microorganisms in the warm, humid environment that is your rebreather.

The purpose of regular cleaning and disinfection is to prevent the multiplication of these microbes to an extent that would pose a hazard to the user and to prevent the transmission of infection between various users.

Not more than a week should be allowed to pass from the first dive after disinfection until the next disinfection if the CCR Liberty is stored in a cool place. When storing the rebreather at a temperature higher than 25 °C (77 °F), this interval is shortened to four days.

I won’t be diving for a few months, how should I prepare the unit for long term storage?

Before storing the rebreather for a period longer than one week, clean and disinfect the unit as usual (see manual section 3.5.3 Cleaning and disinfection).

Watch our tutorial video here.

If the CCR Liberty is stored in a dry and clean environment, do not connect the corrugated-hose assembly with the DSV to the head or to the breathing bags and store the rebreather open. Dust occurs even in an environment with the same level of cleanliness as the home environment. Limit accumulation of dust by, for example, covering the unit with a washed cotton bed sheet. Store the detached corrugated hose assembly in a suitable ventilated container that will allow complete drying.

If you store the CCR Liberty in an environment with a lower degree of cleanliness, store it assembled and closed (without sorbent). Such an environment with a lower degree of cleanliness may be, for example, a home with pets.

Before putting the closed rebreather in storage, all parts must be thoroughly dried, including all creases in the corrugated hoses and the interior surface of the bags.

Charge the batteries at least once every six months.

If, after storing the unit for more than a month, you find that moisture persisted inside the apparatus or you can smell mustiness or mold from the corrugated hoses, it is necessary to disinfect the apparatus again. When storing the rebreather, make sure that no rubber parts (hoses, cables) are pinched or compressed.

Ensure that no other objects are leaned against the rebreather. Secure the rebreather against falling.

Is there a way how to seal the scrubber canister, to protect the sorbent?

Yes, we recommend using the DIVESOFT "Scrubber cover with stickers". It is advisable to write the date of the first filling and the times of the individual dives on which the scrubber was used. After changing the sorbent, change the label.

Do not store used and closed scrubber for more than 30 days after first use.

Trouble-shooting

What do I do if the unit floods?

The probability of the unit to flood significantly is very low if proper procedures are followed. After carefully assembling the apparatus and performing the prescribed pre-dive procedures, flooding can be ruled out unless there is a major disruption of the breathing loop’s integrity due to mechanical damage. In the event of significant flooding, it is necessary to immediately switch to the bailout breathing apparatus and to use the compensator (BCD) to prevent loss of buoyancy.

Do not inhale from the loop if the mixture from the rebreather’s DSV contains fluid. In extreme cases, this could contain a so-called caustic cocktail, i.e. a caustic mixture with dissolved lye from the sorbent.

A smaller amount of water can enter the loop through an open DSV when the mouthpiece falls out of the diver’s mouth. In such a case, water enters into the exhalation bag. Though this does not represent an catastrophic emergency, it is advisable to expel water from the exhalation bag via the overpressure valve as soon as the opportunity arises. Open the overpressure valve completely. Be sure to stabilize your buoyancy in order to avoid a significant loss of buoyancy control. Add diluent to the circuit with the manual bypass valve and perform a diluent flush. Assume a position that brings the overpressure valve to the lowest point of the exhalation bag. Expel the water from the bag by exhaling and pressing on the bag with your hand. This skill will be taught to you by your instructor and it is important to be adequately performed with routine practice.

My Helium sensor won’t calibrate?

If you try to calibrate Helium sensor with any success, please try to dry the helium sensors out. Helium sensors are sensitive for moisture condensation. The moisture condenses directly inside the sensor; neither perfect drying of Liberty head does not remove the condensate from the parts inside of the sensors. When the Helium sensor shows Error or not calibrated, it probably needs maintenance.

For the maintenance you will require a 3mm Hex key.

Procedure:

  1. Disconnect the power by removing battery jumpers.
  2. Remove oxygen cells block by removing 2 screws and pulling out. No component should require excessive force ever!
  3. Remove helium sensors by removing screw and proceed to pull by two finger grip.
  4. Suck the condensate from both sides using mouth. Never blow into the sensor by mouth or any tools. This could cause even the smallest overpressure of air flow to damage the sensitive membrane inside the sensor. This damage will void any warranty and is not covered. Once moisture is sucked out then leave sensors to dry out in dry, warm place.
  5. Once sensors have been left to dry, reinstall to compartment and tighten screws.
  6. Re-insert oxygen sell block and tighten both screws.
  7. Turn on unit power by inserting jumpers to batteries.
  8. Proceed to calibrate helium sensors (Surface mode main menu/Setup/Calibration/Calibrate He-air).

Watch our tutorial video here.

Handset/Buddy/Head up display flooded?

In this scenario, you should send the flooded handset/buddy/HUD to a Liberty authorized service technician or directly to our factory. Please contact us and we can recommend you to the nearest service point to you.

One battery seems to be not working, what now?

If one battery shows you a different sign than you expect (e.g. low battery if you charged) and the second battery is working properly? First, please check the charger and its functionality.

If the charger is working correctly, please change the batteries by switching their locations on the unit head. This will check whether the battery is defective on the other half of the Head. If you find out that the battery is misfunction, please replace it.

If you find out that the problem is not on side of the battery, problem is probably concerning of handset or control unit. Then please check the functionality of the handsets. Follow the same procedure as with the batteries to check connection. Change them and connect them to unit head.

Please note that service of handsets or control units are provided by Liberty authorized service technician or directly at our factory. Watch all process on our tutorial video here.

The battery OPV got pushed out and white fluid is coming out?

In this case, you should send battery OPV to a Liberty authorized service technician or directly to our factory. Please contact us and we can recommend you to your nearest service center.

How to update firmware?

The CCR Liberty’s electronics have two different types of firmware (FW): one for the control unit and another for the handset. It is possible to download the current version here, from the firmware.

Perform updates with the head removed from the rebreather’s body. It is necessary update both CU and handset FW, different versions of CU and handset FW may result in unexpected behavior.

An exact description to follow can be found in your Liberty manual (pp. 75 – 77).

After updating new Firmware 2.11 my Liberty unit is not working correctly. How can I fix it?

First, please disconnect the GPS module (if attached), then download and update Firmware manager. If the trouble persist, update new firmware version again. If after several attempts at re-installing firmware the problem continues to persist then please contact us per email and send us pictures from “System check“ which you find in your control unit Menu screen.

During my dive some water got inside of the Liberty Head. What can I do?

Please be aware that there is a chance that it was not flooded completely and you can do many things to prevent the worst. Watch our video here.

If drying the Head and sensors did not help you, make a calibration of the helium sensors (Surface mode main menu/Setup/Calibration/Calibrate He – air). Otherwise please reach out to us, so that we can lend assistance.

Directional valves are leaking?

First check the valve on any signs of damage. If the valve appears to be damaged, replace it.

Beware of silicone based greases, as they can damage the mushrom valve.

Note that wet directional valves can slightly leak under differential pressures higher than 10kPa. (For example if you blow against the valve very hard with your mouth.) This has no effect on their function under normal conditions (which represents differential pressure less than 1kPa).

Travelnig with rebreathers

Can I fly with my rebreather?

Of course, many rebreather divers travel all across the globe to fully enjoy their rebreather around the world. Please watch our video here.

How to pack my unit for transportation?

Very often we separate the head from the unit and place the head in a carry-on bag and the rest of the unit should be in a checked-in luggage. A majority of our instructors recommend using the Pelican Air 1615 Case for air travel. Please do not transport it in standby mode. Batteries must be disconnected by removing or turning the battery jumpers.

Do I need to bleed the tanks?

Yes! Airline regulations require that all transported pressure tanks must be empty with valves removed. Place the valves in clean PE bags (Ziploc) and place tape over the neck to prevent contamination. It is possible that security personnel will want to look inside the tanks. Therefore it is not appropriate to use tight plugs that cannot be removed without tools.

Can I have my rebreather as carry on?

Most airlines restrict carry-on baggage weight. We recommend to separate Liberty Head and transport it in the hand luggage. You will significantly reduce the weight of your luggage and moreover you will protect the most sensitive part of your device.

How should I behave going through security with my rebreather?

Most airline personnel and security staff do not know what technical diving equipment is, or rebreathers. It can be very helpful to travel with appropriate documentation such as the Liberty manual or the manufacturers shipping checklist but be sure to always remain very calm and most importantly to allocate at least double the time it would normally take to travel through security so as to remove any stress as this process can take a while.