Section: 1. Technical design

1.1 Basic schematic

1.2 Dive/surface valve

1.2.1 Inhalation valve
1.2.2 Exhalation valve
1.2.3 Mouthpiece
1.2.4 Usage with a full face mask

1.3 Corrugated hoses and accessories

1.3.1 Hoses
1.3.2 Attachment to the head
1.3.3 Connection to the breathing bags
1.3.4 Attachment of the DSV

1.4 Inhalation bag

1.4.1 Automatic diluent valve
1.4.2 Manual diluent bypass valve

1.5 Exhalation bag

1.5.1 Manual oxygen bypass valve

1.5.2 Overpressure valve

1.6 Oxygen cylinder

1.6.1 Cylinder
1.6.2 Valve
1.6.3 Reduction valve
1.6.4 Pressure reading

1.7 Diluent cylinder

1.7.1 Cylinder
1.7.2 Valve
1.7.3 Reduction valve and pressure reading
1.7.4 Backup regulator (optional)

1.7.5 Air integration (2021 Edition only)

1.7.6 Transmitters (2021 Edition only)

1.7.7 Procedure for pairing the transmitter (2021 Edition only)

1.8 CO₂ scrubber

1.9 Head

1.9.1 Control units
1.9.2 Direct measurement of ppO₂
1.9.3 Measurement of He content
1.9.4 Helium blind plugs
1.9.5 Pressure and depth measurement
1.9.6 Temperature measurement
1.9.7 Solenoids
1.9.8 Power supply

1.10 Visual display units

1.10.1 Handsets
1.10.2 Head-up display
1.10.3 Buddy display

1.11 Backplate and mounting

1.12 Harness

1.13 Buoyancy compensator

1.14 Ballast

1.15 Weights of individual parts

1. Technical design

1.1 Basic schematic

The principle of a rebreather involves in recycling the breathing mixture. Carbon dioxide is removed from the exhaled mixture and is again prepared for the next inhalation after being replenished with oxygen. The composition of the breathing mixture changes continuously.

The inhalation valve is situated within the connection of the left corrugated hose.

A similar mushroom valve can be found in the exhalation valve an open circuits’s second-stage regulator.

This is one of the most critical components of the rebreather. It is, however, difficult to detect a malfunction in this part during a dive, and such a malfunction can lead to loss of consciousness.

1.2.2 Exhalation valve

The exhalation valve directs the exhaled mixture via the corrugated hose to the exhalation bag. It prevents the diver from directly re-inhaling the exhaled mixture.

The exhalation valve is situated within the connection of the right corrugated hose.

1.2.3 Mouthpiece

Creating a tight seal around the rebreather’s mouthpiece prevents water from entering into the circuit. The DSV and corrugated hoses function at a greater force than the regulator of an open-circuit apparatus. Therefore having, an anatomically suitable mouthpiece and proper clenching of the mouth is critical.

We do not recommend using a mouthpiece that can be shaped to the diver’s bite after heating. This kind of mouthpiece restricts the movement of the lower jaw, which leads to unilateral stress and will rapidly exhaust the masseter muscles.

1.2.4 Mouthpiece Retaining Strap

EN 14143:2014 requires the use of a strap to securely connect the mouthpiece to the diver's mouth. The retaining strap is intended to reduce the likelihood of potential water ingress into the breathing loop or drowning of the diver in the event of unconsciousness or convulsions. The Mouthpiece Retaining strap in the basic Liberty package is designed with a rubber elastic cord mounted on the DSV. Adjust the tension and force of the restraint by tightening or loosening the fisherman's knot. This basic solution can be user upgraded with optional accessories on the Divesoft shop.

1.2.5 Usage with a full face mask

Even though the mechanical dimensions of the DSV would allow for the connection of a full face mask, it is not possible to switch an open-circuit mixture inlet with an inlet from a rebreather. One of the reasons for this is the necessity of defogging the visor.

Consult with the manufacturer regarding possibilities of connecting a full face mask to the rebreather. The use of such an apparatus will require procedures that deviate from this manual and from standard procedures taught in a course accredited by the rebreather’s manufacturer.

1.3 Corrugated hoses and accessories

1.3.2 Attachment to the head

Unlike almost all other bayonet connectors on the CCR Liberty, the bayonet connector on the exhalation side has three protrusions. This design prevents incorrect attachment of the hoses, since the inhalation side has only two protrusions.

Elbow on the exhalation side (left) and inhalation side (right).

1.3.3 Connection to the breathing bags

The T-pieces have standard bayonet connections. On the exhalation side, the T-piece has a partition that directs any water that has entered the DSV to the exhalation bag and improves the blending of the mixture when oxygen is added via the manual bypass valve.

1.4 Inhalation counterlung

The inhalation bag is affixed to the harness with two stainless-steel buckles and is secured with Velcro flaps. It can be easily removed for cleaning, disinfecting, and other handling.

See also section 3.5.3 Cleaning and disinfection.

1.4.1 Automatic diluent valve

The automatic diluent valve (ADV) is mounted in the middle bulkhead with a bayonet connector.

When the volume of the inhalation bag decreases, the ADV is pressed, and diluent is automatically added to the breathing circuit.

The ADV can be closed by sliding the collar.

The sensitivity of the ADV can be decreased with an additional spring, which is included as a spare part.

1.4.2 Manual diluent bypass valve

The manual diluent bypass valve is situated in the lower bulkhead of the inhalation bag and is equipped with a bayonet connector.

The valve is attached to the low pressure (LP) hose with a seatec-style quick-release connector.

It is operated by pressing the center button.

The safety lock prevents diluent valve from accidentally falling out. Keep this information in mind when removing the valve.

This connector is like a standard seatec-style quick-release connector with a collar.

A standard connector cannot be connected to the oxygen quickrelease connector, though, it is possible to connect the oxygen hose to the normal connector.

Do not remove the collar from the oxygen connector as connecting the wrong gas to the wrong valve could potentially be dangerous. This is a requirement of the EN 14141 norm.

The bayonet connector on the oxygen bypass valve has three protrusions.

Use oxygen-compatible lubricant for maintenance of the oxygen bypass valve (We recommend DuPont Krytox GPL-226).

A safety lock prevents the OPV from accidentally falling out. To remove the valve push it in to unlock, and rotate in the direction of the arrows. Indicated on the valve.

1.6 Oxygen Cylinder

1.6.1 Cylinder

The CCR Liberty uses a three-liter steel cylinder with 100 mm diameter and has a 200 bar filling pressure. The original 300 bar filling pressure of the cylinder was changed according to valid technical standards.

The cylinder is labeled OXYGEN and is situated on the diver´s right side when wearing the CCR Liberty.

When connecting the oxygen cylinder to the unit, make sure the cylinder is in an upright orientation before tightening the handwheel on the oxygen first-stage regulator. Trying to straighten the cylinder when it is already screwed in will put tension on the threats and will be hard to remove without the help of tools.

For more information on filling, see section 3.2.5 Oxygen.

WARNING: The cylinders and valves are made of oxygen compatible materials and all components have been oxygen cleaned during their manufacture. However, unless assembled by a certified service technician, they cannot be considered oxygen clean.

1.6.2 Valve

The oxygen cylinder valve has a M26×2 200 bar outlet connection according EN 144-3. The valve is not compatible with standard 12209:2013 (formerly also known as DIN) valves to eliminate possible mix-up between oxygen and diluent cylinders, this is a requirement of the EN 14141 norm.

1.6.3 Reduction valve

The CCR Liberty uses an Apeks DST4 first-stage regulator with a specially made low-pressure turret mounted on the backplate that serves as a lower cylinder-mounting point. A Velcro strap wraps around the middle of the cylinder to secure it to the unit.

The reduction valve is equipped with an intermediate-pressure safety overpressure valve.

WARNING: 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. This does not apply to the Sidemount version, which uses first stages without a dry chamber.

1.6.4 Pressure reading

The oxygen pressure gauge is situated on the diver’s right side; the HP hose runs through an opening in the backplate.

The 2021 Edition Liberty features wireless cylinder pressure readings for both oxygen and diluent cylinders and one bailout mixture. In this case, after setting this option and placing pressure transmitters on the first stage regulators, it is possible to display the cylinder pressure on the handset display.

1.7 Diluent cylinder

1.7.1 Cylinder

The CCR Liberty uses a three-liter steel cylinder with 100 mm diameter and 230 bar filling pressure. The original 300 bar filling pressure of the cylinder was changed due to utilizing a 230 bar valve.

The cylinder is labeled DILUENT and is situated on the diver’s left side when wearing the CCR Liberty.

For more information on filling, see section 3.2.5 Diluent.

1.7.2 Valve

The diluent cylinder valve has a ISO 12209:2013 230 bar outlet connection (formerly also known as DIN G 5/8).

1.7.3 Reduction valve and pressure reading

The design is similar to that of the oxygen cylinder, only mirrored.

WARNING: 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. This does not apply to the Sidemount version, which uses first stages without a dry chamber.

1.7.4 Backup regulator (optional)

The second stage of a regulator may be connected to the output of the diluent first-stage via a LP hose of an appropriate length. This regulator can be used as a backup if the diluent at a given depth is breathable (oxygen partial pressure between 0.16 and 1.6 bars).

Having the backup regulator connected to the diluent may be useful for sanity breaths and for prolonged switching to a backup apparatus.

However, it is advised to use the bailout only in special circumstances, such as when diving in extremely shallow water.

1.7.5 Air integration (2021 Edition only)

You can use any compatible transmitter (not included). For example, Shearwater / Aqualung / Pelagic (Suunto, Ratio, Mares, Garmin, Scubapro smart are not compatible). The transmitter is automatically activated by pressurization to 8 bar and more. The transmitter turns off after 2 minutes at a tank pressure of <4 bar. Please do not leave the Liberty pressurized for prolonged periods of time (at storage), since the transmitter has declared runtime of 300hrs on one battery

1.7.6 Transmitters (2021 Edition only)

In the case of multiple transmitters, it is advisable to use yellow + grey, not two grey ones

• • More than two (max. three) transmitters are not recommended; random long signal
• dropouts can occur even when using two transmitters of the same color.
• • On the back-mounted unit place the transmitters with HP elbows to first stages. Factory
• tested orientation is parallel with the backplate – pointing to the other 1st stage.
• Sidemount unit doesn’t need any elbows. It is advisable to install the transmitter on a short
• HP hose (15 / 20cm) to prevent breaking off the transmitter accidentally.
• • Range – approx. 0.7–1m, rather less than more.

1.7.7 Procedure for pairing the transmitter (2021 Edition only)

• • Pair the transmitter Setup / Wireless / Air integr.
• / Oxygen or Setup / Wireless / Air integr. /
• Diluent
• • If the transmitter is turned on and within range, it should have a serial number in the menu
• • Otherwise, set the last 6 digits of the serial number of the station via “Edit”

If you do not see any sensors, try repositioning the transmitters. Change the position of the transmitters in small steps and always wait at least 10 seconds in each position. Always set the transmitters one at a time. The position of the transmitters, their response or signal errors are the subjected to your feedback.

Signal failures

• • <60 sec… holds the last value
• • 60 <90sec… old value is still legible, bargraph grey
• • > 90 sec… blank frame, instead of dash value only
• • c. Low transmitter battery – If one of the alarms below persists, replace the transmitter
• battery.
• • “Running out of battery” – an almost empty battery is drawn over the bar graph every 5
• seconds
• • “Empty battery” – a bold “B” is drawn every 5 seconds

1.8 CO₂ scrubber

The walls of the cartridges are fabricated with external and internal metal mesh. A metal disc presses down on the scrubber cartridge by means of a spring-loaded pressure plate. The pressure plate is fastened to the central tube with a retaining ring.

The scrubber cartridge capacity is pproximately 2.5 kg of sorbent. The sorbent volume is approximately 2.82-2.99 l.

The service life and replacement of the sorbent are described on section 3.2.1 Replacement of CO₂ sorbent.

If it is difficult to remove the head, place the rebreather on a hard surface with the pin pointing downwards, as shown in the illustration. Press down on the head and the scrubber canister with your hands.

1.9.1 Control units

The control units (CUs) are independent, and each is connected to its own display unit or handset (HS). Each CU is equipped with its own power source, solenoid, temperature and pressure gauge, as well as its own, O₂ partial pressure and He concentration sensors

If one control unit fails, the other control unit takes over automatically.

CUs and HSs are independent computers communicating via a bus. Each handset displays the activity results of both CUs and is used to control both CUs. Each HS is powered by the corresponding CU. In the event both handsets malfunction, both, or one of the remaining CUs will continue to regulate ppO₂ according to the last adjusted setpoint.

If communication between the CUs breaks down, each unit will continue to control its own solenoid. The control algorithm is sufficiently robust to prevent any ppO₂ deviations from the allowed limits during dual, parallel regulation.

Connection to a personal computer

The memory of the operating protocols and content of the memory card can be read using a USB adapter connected to the handset connector as a mass storage device (like a flash drive). The connection to Windows, Mac, Linux, Android and iOS was tested, however there is no guarantee of compatibility with all operating systems and computers.

When using the USB connection, the control unit is powered from the USB port and, at the same time, the battery is being charged.

Each control unit contains the same dive logs; only one control unit needs to be connected to download the logs on a computer.

Another option is to connect the device via Bluetooth. To do this, you need to download a software for Mac or PC. It can be found at Divesoft.Center.

You can also download recordings wirelessly using your mobile phone with the Divesoft.App. You can also send error messages using this app. The app downloads the dive and system records and sends them to the responsible DIVESOFT staff for review.

1.9.2 Direct measurement of ppO₂

To measure ppO₂ only use DIVESOFT R22D-type sensors. The usage of other sensors from other manufacturers is prohibited.

Two oxygen sensors are connected to each CU, and all sensors are located on the inhalation side. Both CUs have access to all four oxygen sensors and are continually exchanging data.

The diver can manually exclude a sensor from operating and can also choose when to reinclude it. Choosing to manually exclude a sensor always has priority over an automatic detection of a faulty sensor. If all sensors are excluded, the CCR Liberty can be switched to a backup algorithm with calculates the partial pressure of oxygen indirectly based off the measured the He content (assuming the used diluent contains >20% He).

Circulation of the mixture in the breathing loop is necessary for the measurement accuracy. If the user does not breathe from the rebreather, the mixture surrounding of the oxygen sensors can have a different proportion of oxygen than in the breathing loop. Thus, the displayed data can be inaccurate.

A similary situation can occur in the event of a rapid descent when a larger amount of diluent is added, or when the setpoint is changed to high, and the ppO₂ in the loop is progressing to the new level.

The sensors are constantly being automatically evaluated. The ppO₂ measured by one sensor is always compared to the average reading of the other sensors. This way, each individual sensor is constantly being cross-checked and monitored for possible deviations. If the average deviation of the sensors exceeds 0.1 bar, the system will automatically exclude the sensor that deviates most from the average.

Only one sensor can be automatically excluded at a time, and only a total of two sensors can be automatically excluded. There will always be at least two sensors that the diver has to evaluate themselves. This procedure is described in section 3.4.4 Monitoring of devices.

WARNING: Sensor exclusion works on the principle of a mathematical algorithm. Despite the efforts of developers to find the ideal risk-control solution, there is still a chance that the excluded sensor could be the only functional one. Always verify your oxygen sensors.

Refer to the chapter “Oxygen sensors” on how to handle and maintain your sensors.

1.9.3 Measurement of He content

The helium concentration is determined by the velocity of sound in the mixture. The He concentration sensors are connected to the inhalation side.

A pressure drop caused by the circulation of the mixture in the breathing loop allows the gas to pass through the sensor.

This principle of measuring the oxygen concentration (and its subsequent automatic conversion on the basis of the known ambient pressure to partial pressure) is used as the backup method of measuring ppO₂ in case all electrochemical ppO₂ sensors malfunction.

Oxygen measuring using helium sensors must be manually turned on in Setup / Faulty sensors / pO₂ source. This method is intended for use only in emergency situations. If possible, use a bailout apparatus.

The use of helium sensors also depends on the CCR Liberty’s settings. For the helium sensor function, the “TMX only” must be selected by going to Menu / Setup / Preferences / He Measurement.

For proper functioning of helium sensors, the sensors must be calibrated regularly. Refer to Helium sensor calibration (see section 3.2.7) for the calibration procedure.

Always keep your helium sensors dry to ensure their long lifetime and functionality (see also section 3.5.1 Immediately after surfacing).

Do not disassemble the sensors, as this may can result in irreparable damage.

WARNING: Do not remove the helium sensors from the unit, even when faulty. Their removal will “short -circuit” the scrubber, which will not be able to filter CO₂ from the breathing mixture.

1.9.4 Helium blind plugs

Included in your CCR Liberty are two helium sensor “blind plugs”. These plugs are designed to act as a spacer so that the user can remove the high-fidelity sensors. The Divesoft helium sensors are highly sensitive to moisture and can be easily corrupted if the moisture is not removed through proper ventilation. It is highly recommended to use our accessory head fan during post dive procedures to remove moisture that could collect within the sensors during diving.

The purpose of these plugs is so that the helium sensors can be removed when the user is not diving with a helium mix. It is recommended that when the user is not diving with a helium gas mixture the user should use the helium blind plugs instead.

To install the Blind plugs:

• — First, take a hex key and remove the oxygen cells block.
• — Once the block is removed then take hex key and remove the hex screw within helium sensor securing sensor to Liberty head.
• — After screw is completely removed then firmly grasp helium sensor and gently remove sensor, take care as to not twist sensor upon removal.
• — Then install the blind plug in the identical orientation as the helium sensor then secure with a hex screw, always be sure to use only two fingers for tightening screw and do not over tighten screws.
• — Repeat this process for opposite side helium sensor.
• — Once both blind plugs are installed and hex screws properly secured then reinstall oxygen cells block, take care as to not over-tighten any screws.
• — Place helium sensors in a labeled small bag and properly store them in a climatecontrolled area to use best practices for your rebreather sensors. They are designed for extreme conditions of rebreather diving, but in order to guarantee their life, they must be properly cared for.
• — During your predive operations when using the blind plugs, the Liberty will show an error – sensor missing. Though the helium sensors are being disabled because the blind plugs are installed. This is expected and will not have any effect on diving operations.
• — If diving with trimix or other helium based mixtures, it is highly recommended that the Blind plugs be removed. And the high-fidelity helium sensors be installed into the Liberty head. Be sure to properly calibrate the sensors on air. Once the sensors are calibrated, check the Setup / Preferences if He measuring is set to “TMX only”. This will guarantee that you have redundant ppO₂ measurement and proper helium measurement in your Liberty rebreather system.

1.9.5 Pressure and depth measurement

Each of the CCR Liberty’s control units uses dual pressure sensors. The first sensor intended for measuring low pressure is used for determining sea level, for calibrating of the ppO₂ sensors, and for improving the accuracy of depth data in shallow water.

The second sensor is intended mainly for measuring hydrostatic pressure. The maximum scope of the sensor corresponds to the depth of 300 m.

1.9.6 Temperature measurement

The temperature in the breathing circuit is measured by temperature sensors within the pressure sensors. The water temperature sensors are situated in the handsets.

Temperature data serves primarilly to supplement the accuracy of other sensor measurements. The water temperature shown on the HS display is only an approximate reading.

1.9.7 Solenoids

The control units communicate with each other and, in normal circumstances, open the solenoid valves, which supply oxygen to the breathing circuit.

The solenoids are opened alternately left – right in a six-second interval. The solenoid opening is indicated in the dive mode by the “=” symbol in the left or right bottom corner of the handset screen.

Failed solenoid detection The solenoids are normally opened alternately left – right after six seconds. If one of the solenoids is defective and still registered as functional, then the oxygen injection interval is actually extended to 12 sec, because the device uses a non-functional solenoid every 6 seconds. In this case, the oxygen supply is insufficiently accurate.

Defective solenoid detection works in case the solenoid is blocked in the closed position or disconnected altogether (connector failure). The electronics verify whether the solenoid responds to stimuli and evaluates whether the solenoid is functional or not. In the event of a malfunctioning solenoid, the diver will receive information on which of the two solenoids is malfunctioning. The diver has the option to disable the faulty solenoid during the dive Menu / Setup / Faulty sensors / Solenoids.

As soon as the diver deactivates the solenoid, the device then uses only one solenoid with an interval of 6 sec.

This is warning only, the device does not deactivate the solenoid automatically.

The warning is issued after multiple failed solenoid responses (cca 30-50sec delay), so do not rely on this warning. Since in a scenario of a “stuck open” solenoid, you will get ppO2 creep or spike long before a solenoid failure warning.

1.9.8 Power supply

The CCR Liberty uses two Li-Ion batteries, one to power each control unit. The minimum service life of Li-Ion batteries is six months. The typical service life of the batteries is two years.

See also section 3.2.6 Battery charging.

The battery compartments are pressure resistant. If overpressure is formed inside of a battery compartment because of battery malfunction or helium diffusion, then an overpressure valve will release excess gases out of the rebreather and into the surrounding water.

Battery specification:

• Type: Li-Ion
• Voltage: 3.6V
• Capacity: 5.7Ah

1.10 Visual display units

1.10.1 Handsets

The handsets provide the CCR Liberty’s user with comprehensive information on the rebreather’s status and the course of the dive. All functions of the control units are controlled using the handsets.

The functionality of both handsets is identical. Each handset controls both CUs simultaneously. In the event of a malfunction of one handset, the diver simply uses the other handset. During a dive, it is possible to set a different display mode on each handset.

For more information on handset operation, see section 2 Control-unit operation.

If you are not entirely sure what the HUD is displaying, check the parameters on the handset display. Always check the HS if the HUD displays a warning (outer LED blinks red) or an alarm (all three LEDs flashs red four times).

See the following table for the various HUD signals.

The brightness of the HUD can be adjusted using Setup / Preferences / Indication / HUD bright. Changing the brightness of the display is only applied in dive mode. In Surface mode, it is not affected.

1.10.3 Buddy display

The buddy display (BD) shows whether the values of the partial pressure of oxygen are within the range that is suitable for breathing or if an error situation has occurred. The displayed information is intended for the diving partner of the CCR Liberty´s user.

Prior to diving, the user of the CCR Liberty must familiarize his/her diving partner with the buddy display’s functionality and agree on the emergency procedure to be carried out in the event that the buddy display indicates an error situation.

See the following table for the various buddy-display signals.

HUD and buddy-display signals

Color blind mode

If you cannot distinguish blue and green LED lights, check “Color blind mode” in Setup / Preferences / Indication. Signals for 1.05 ≤ ppO₂ ≤ 1.65 will be changed according the following table:

1.11 Backplate and mounting

The method of mounting the CCR Liberty on the diver’s body is based on the backplate and harness common among wing-type buoyancy compensators used in technical diving.

The body of the rebreather, comprised of the scrubber canister and the attached head is mounted to the backplate with a cam. The cam lever cannot be released when the diver is wearing the rebreather.

The CCR Liberty’s integrated stand, which serves as a lumbar support, is intended for setting the rebreather on a hard, level surface with sufficient rigidity. Always secure the standing rebreather to prevent falling.

If needed, it is possible to remove the CCR Liberty’s backplate, and use it with a harness for open-circuit diving. The backplate enables the attachment of a twin-set (two cylinders firmly connected with stainless steel bands) commonly used in technical diving, as well as attachment of a single cylinder.

When mounting the CCR Liberty onto the backplate, set the bottom of the scrubber cannister into the protrusion in the rebreather stand.

1.12 Harness

The backplate is equipped with a harness that is to ensure proper system functioning. Do not change the way was intended to be used. If you do try to take the harness out, record exactly how it is threaded to prevent an interference with the functionality of the whole system.

It is necessary to adjust the harness to ensure a proper fit. Adjust the harness without the mounted scrubber canister, head, corrugated hoses, and breathing bags.

Adjust the length of the shoulder straps to where three fingers can easily fit under the straps at the collar-bone level.

The chest D-rings should be as low as possible, while still allowing you to cross your arms over your chest comfortably. The D-rings should be high enough for you to reach the left ring with your left thumb and the right ring with your right thumb. The D-ring on the left side of the waist strap should be roughly on your hip.

Adjust the length of the left part of the belt strap so that it passes through the eye of the crotch strap with approximately 5 cm (strap width) still remaining between the ring and the eye. Adjust the right part so that the strap is slightly tight. If you shorten a strap, leave sufficient room for different suits or a possible change in body dimensions. After shortening, it is necessary to deburr the ends of the straps by heat sealing them with a cigarette lighter or candle. Do this carefully to avoid forming a hard surface on the strap ends.

Adjust the length of the crotch strap so that it lies closely against the body but does not dig in. Set the position of the rear D-ring as low as possible but high enough so that it does not place pressure on the buttocks when swimming. The rear D-ring should be within the diver’s reach. Test the exact position of the rear D-ring in the water with the complete apparatus.

1.13 Buoyancy compensator

The CCR Liberty uses a wing-type buoyancy compensator (BCD) with a displacement of 200 N. The compensator’s design and materials are very durable and even suitable for cave and wreck diving.

The wing has a two-ply design. The internal bladder is made of high-frequency-welded Cordura 560 fabric with PU coating. The wing’s external cover is made of Cordura 2000 fabric.

The wing is attached with screws along the edge of the backplate.

To correctly position the inflator, pass the low-pressure hose through the rubber ring on the corrugated hose, then through the rubber ring on the shoulder strap and finally through the second rubber ring on the corrugated hose. Do not skip either of the rings on the corrugated hose; upon disconnecting the quick-release connector from the inflator, it could move far enough back to where it is hard to find or reach.

The buoyancy compensator is not a life preserver. It does not maintain the diver in a face-up position. It is not designed to hold the diver’s face above the surface should he/she become unconscious or immobile.

1.14 Ballast

The ballast system is composed of two pouches positioned on the sides of the scrubber canister and are attached to the cylinders. In the lower part of the pouches, there is a loop through which the attachment strap of the rebreather body is passed. The internal pouches, which contain the individual weights, are inserted into the external pouches. The upper flap of the external pouch is intended for inserting weights before a dive and removing them after. For emergency jettisoning of ballast, pull the red strap on the lower part of the pouch. This will open the external pouch and will release the internal pouch containing the ballast.

For regular ballast removal, do not use the method for emergency jettisoning. This could lead to excessive wear of the Velcro.

A diver in a dry suit typically needs 2×4 kg of ballast. Proper ballast weight and distribution is a subject covered in the CCR Liberty diver course.

1.15 Weights of individual parts

The listed weights are merely an indication. The weight of the parts of each apparatus may vary.

• Backplate with the wing, harness and hoses, without counterlungs ........ 10.68 kg
• Weight pockets (without weights) ...................................................................... 0.43 kg
• Counterlungs incl. all valves.................................................................................1.86 kg
• Cylinder with valve, empty .......................................................................................... 5.44 kg
• Corrugated hose, complete .................................................................................. 1.11 kg
• Scrubber body and cartridge, without sorbent ................................................ 3.76 kg
• Head incl. handsets, HUD and BD ....................................................................... 4.59 kg
• Charger with cable ................................................................................................ 0.09 kg
• Supplied accessories and small parts (without chargers) ............................1.00 kg
• Peli Stormcase iM2975 ....................................................................................... 10.30 kg
• Oxygen 3 l at 200 bar ............................................................................................ 0.84 kg
• Diluent (air) 3 l at 300 bar ................................................................................... 0.91 kg
• Sofnolime ............................................................................................................... 2.50 kg
• Energy stored in batteries ...................................................................... 4.16×10-11 kg