Rebreathers From the First Closed Breathing Loops to Modern Exploration Diving
Comprehensive History & Introduction · Part 1 · Expanded Edition
“Understanding the machine before trusting the machine.”
Introduction
There is something almost paradoxical about the history of the diving rebreather. Many divers instinctively think of the rebreather as one of the most modern forms of underwater breathing technology - a machine associated with electronic oxygen controllers, decompression computers, trimix, cave penetration, deep wrecks and expeditionary dives measured in hours.
Yet the fundamental principle of the rebreather is older than modern open-circuit scuba. Long before Cousteau and Gagnan popularized the Aqua-Lung, engineers were already trying to conserve exhaled breathing gas rather than discard it into the surrounding environment.
The idea is deceptively simple: remove carbon dioxide from the exhaled breath, replace the oxygen the body has metabolically consumed, and breathe the remaining gas again. The materials, sensors, electronics and operating procedures have changed enormously. The central idea has not.
The history is also broader than diving. The same regenerative breathing principle developed along several parallel paths: mine rescue, firefighting, toxic-atmosphere work, submarine escape, military combat swimming, scientific diving and, much later, civilian recreational and technical diving. Understanding those parallel histories explains why rebreathers remained specialist equipment for so long - and why the modern sport-diving rebreather revolution did not truly begin until the 1990s.
1.Before the Rebreather - The Problem of Breathing in Hostile Environments
For most of human history, underwater activity was limited by a basic problem: humans cannot breathe underwater. Early divers depended on a single breath, diving bells, or air supplied from the surface. Similar problems existed on land wherever smoke, poisonous gas or oxygen deficiency made the atmosphere unbreathable.
Surface-supplied systems solved part of the problem but tied the user to a hose. In a flooded tunnel, mine, burning structure, submarine or underwater cave, that hose could become the limiting factor. Engineers therefore searched for a self-contained breathing apparatus that could carry its own usable atmosphere and regenerate it as efficiently as possible.
Two technological families eventually emerged: open circuit, in which gas is breathed once and discarded; and rebreathing systems, in which useful gas is retained, carbon dioxide is removed and oxygen is replenished.
2.The Earliest Regenerative Breathing Concepts
Ideas for chemically regenerating breathing gas appeared during the nineteenth century. Theodore Schwann described a regenerative apparatus in the 1850s, while other inventors patented related concepts. These early developments were not yet the compact diving rebreathers we know today, but they established the chemistry and architecture that made closed breathing circuits possible.
The crucial practical step came with Henry Albert Fleuss of Siebe Gorman.
3.Henry Fleuss - The Practical Self-Contained Rebreather, 1878
In 1878 Henry Fleuss developed what is widely regarded as the first practical self-contained closed-circuit breathing apparatus. It carried oxygen, used a breathing reservoir and chemically absorbed carbon dioxide from exhaled gas. The diver could therefore reuse the breathing gas instead of exhausting every breath into the water.
The modern rebreather diver would immediately recognize the essential loop: diver → exhaled gas → carbon-dioxide removal → oxygen replacement → diver. Modern scrubbers, valves, sensors and electronics are far more sophisticated, but the fundamental process is the same.
4.Fleuss, the Severn Tunnel, and the First Great Operational Advantage
Fleuss tested the apparatus himself, and the design soon found a dramatic practical use. During work on the flooded Severn Tunnel, diver Alexander Lambert used Fleuss-type equipment in 1880 to penetrate deeply into the submerged works and operate valves where conventional air hoses were a severe obstacle.
That event revealed one of the defining advantages of rebreathers: independence from a large external gas supply. In 1880 it meant eliminating a surface hose. In modern exploration it can mean dramatically reducing the gas logistics for a deep wreck or a multi-kilometre cave penetration.
5.Rebreathers Above Water - Mine Rescue and the Birth of the “Draegermen”
The same regenerative principle quickly proved valuable in mines and other poisonous or oxygen-deficient environments. Dräger became particularly important. Bernhard Dräger focused on respiratory protection from the beginning of the twentieth century, and the company’s Model 1904 rescue apparatus became a major success in mine rescue. Dräger equipment became so closely associated with mine-rescue teams in North America that rescuers were widely known as “Draegermen.”
Siebe Gorman developed the Proto oxygen rebreather for industrial rescue. It used an oxygen cylinder, breathing bag and carbon-dioxide absorbent and became a standard tool in British mine rescue. These were not diving sets; they were life-support machines for hostile atmospheres. But technologically they belong directly to the rebreather family.
6.Firefighters - Rebreathers in Smoke and Toxic Atmospheres
Firefighters also adopted closed-circuit breathing apparatus. The London Fire Brigade records the adoption of Siebe Gorman’s Proto in 1914 after earlier hose-fed smoke helmets had limited mobility. The oxygen rebreather allowed trained firefighters to work independently inside smoke-filled buildings.
Rebreather-type firefighting apparatus remained in service for decades. In several fire services, Proto and Salvus sets survived into the post-war era; later closed-circuit units such as Dräger’s BG series were used for long-duration industrial and firefighting work. Modern fire services generally favor open-circuit compressed-air SCBA for routine structural firefighting, but closed-circuit rebreathers remain important where exceptionally long duration is required, especially in mine rescue, tunnelling and specialized industrial rescue.
This parallel history matters: rebreathers were proven life-support technology long before they were a mainstream sport-diving product.
7.Submarine Escape - Dräger Tauchretter and the Davis Submerged Escape Apparatus
At the beginning of the twentieth century, navies faced another hostile-environment problem: how could submariners escape from a disabled submarine without relying on an external air supply? Dräger developed a Tauchretter for submarine crews in 1907. In Britain, Sir Robert Davis developed the Davis Submerged Escape Apparatus, introduced around 1910.
These were principally escape-rescue apparatus. They could provide a breathing gas reservoir during the escape ascent and, in some designs, buoyancy assistance. This is an important correction to a common recollection: although respiratory protection was also relevant aboard submarines in smoke or contaminated atmospheres, the classic Tauchretter and DSEA lines were fundamentally conceived as submarine escape systems rather than primarily as onboard firefighting respirators.
However, the technological family was the same one already being used in mines and fire brigades: oxygen supply, a breathing bag, carbon-dioxide absorption and recirculation.
8.Hans Hass - Turning a Rescue Apparatus into a Swimming Diver’s Rebreather
Hans Hass occupies a special place in rebreather history because he helped demonstrate that an oxygen rebreather could be more than a rescue device or military tool: it could become a practical autonomous swimming-diver system for research, photography, natural history and filmmaking.
During the early 1940s Hass worked with Dräger engineer Hermann Stelzner on modifications derived from Dräger’s Gegenlunge/Tauchretter technology. The counterlung was moved to the diver’s back, the arrangement was adapted for horizontal swimming, and oxygen addition was brought under practical diver control. Hass used the resulting regenerative diving equipment during his 1942 Aegean expedition. Post-war development led to the Dräger Kleintauchgerät Model 138.
Hass’s contribution was therefore not the “Leutnant Lund” rebreather - that came later, in the 1950s. His historical importance lies in helping transform rescue-derived oxygen-rebreather technology into equipment optimized for the free-swimming scientific and photographic diver.
Through books, lectures and films, Hans and Lotte Hass also gave millions of people their first view of silent autonomous underwater exploration. In that sense, Hass was not merely an early rebreather user; he was one of the first major civilian ambassadors for the concept.
9.Leutnant Ove Lund - A Later Military Development, Not the Hass Rebreather
The famous Dräger “Leutnant Lund” series belongs to the next chapter. Norwegian naval officer Ove Lund trained with U.S. Navy Underwater Demolition Team personnel in the early 1950s and gained experience with the Dräger Kleintauchgerät 138. Working with Dräger, he pushed for longer endurance and military usability.
The resulting Leutnant Lund I and II oxygen rebreathers increased oxygen capacity and refined the equipment for naval frogmen. They were used by Scandinavian and other naval units and became an important bridge between the earlier Kleintauchgerät and later purpose-built combat-swimmer systems.
The distinction is worth keeping clear: Hass helped establish the free-swimming civilian/scientific use of the earlier Dräger-derived oxygen set; Lund later helped drive its evolution as military combat-swimmer equipment.
10.Oxygen Rebreathers - Extraordinary Efficiency, Severe Depth Limits
Pure oxygen closed circuit is extraordinarily efficient because the diver only needs replacement oxygen for what the body metabolically consumes. Almost all remaining gas is recycled. This permits long endurance from small cylinders and virtually bubble-free operation.
But oxygen partial pressure rises with ambient pressure. Pure oxygen therefore imposes a shallow depth envelope because central nervous system oxygen toxicity can become life-threatening. This physiological limit shaped rebreather history: oxygen units remained ideal for shallow combat swimming and special work, while deeper operations demanded mixed-gas systems.
11.World War II - Combat Swimmers, Human Torpedoes and the Italian Maiale
The Second World War demonstrated the tactical value of bubble-free oxygen rebreathers on a dramatic scale. Italian, British and German forces used closed-circuit oxygen equipment for combat swimming, harbour penetration, underwater demolition and clandestine reconnaissance.
Italy’s Decima MAS became famous for the Siluro a Lenta Corsa - the slow-running human torpedo nicknamed the “Maiale,” or “pig.” Two combat divers rode the torpedo toward an enemy anchorage, breathing from oxygen rebreathers so that their exhaust would not betray them. They could detach explosive warheads and place them beneath ships before attempting to escape.
The 1941 raid on Alexandria, in which Italian operators severely damaged the British battleships HMS Queen Elizabeth and HMS Valiant, became one of the iconic demonstrations of the strategic potential of combat divers and rebreathers.
The same characteristics that make a CCR attractive to a modern wildlife filmmaker - silence, minimal bubbles and long endurance - made oxygen rebreathers valuable military tools.
12.The Cold-War Combat-Swimmer Line - Dräger LAR
After the war, military rebreather development continued largely away from the recreational market. Dräger’s LAR family became one of the best-known Western combat-swimmer rebreather lines. These compact oxygen closed-circuit units were designed for shallow, covert operations where low acoustic and visual signature mattered more than extreme depth.
The LAR V, introduced in the 1970s, became especially well known and was used by military special-forces and naval combat-swimmer units. Modern descendants such as the LAR 8000 retain the military emphasis on low signature, ruggedness and specialized mission configurations.
The LAR story illustrates why rebreathers remained strongly associated with the military for decades: they solved a tactical problem open circuit could not solve nearly as well.
13.Mine Countermeasures and Underwater Work - Dräger FGT
A parallel Dräger branch addressed mine-countermeasure, explosive-ordnance-disposal and underwater work requirements. The FGT - FertigGasTauchgerät - line used premixed breathing gases in semi-closed operation, while some versions could also operate on oxygen closed circuit.
The early FGT-1 appeared around 1969. Modern FGT 5400 systems are designed specifically for MCM/EOD diving, with non-magnetic construction to reduce the risk of triggering magnetically influenced mines. Depending on premix, the system supports substantially greater depth than a pure oxygen combat-swimmer rebreather.
This distinction between LAR-type shallow covert oxygen systems and FGT-type mixed-gas mine-clearance/work systems became an important part of military rebreather specialization.
14.The Soviet and Russian Tradition - IDA Rebreathers
The Soviet Union and later Russia developed their own extensive family of closed-circuit apparatus. The IDA series - from “isolating” or individual breathing apparatus - served naval, military, aviation and rescue roles.
The IDA-71 became one of the best-known Russian military rebreathers. In its standard naval form it is an oxygen closed-circuit unit with absorbent canisters and provision for mission equipment; optional arrangements allowed mixed-gas use. Related Soviet/Russian systems covered combat swimming, submarine escape, high-altitude breathing and specialist underwater operations.
After the end of the Cold War, surplus IDA units occasionally entered Western civilian hands and some were converted by technically skilled divers into manually controlled recreational or technical rebreathers - another example of military technology migrating into sport diving.
15.The United States - Lambertsen, Mixed Gas and the Military CCR Tradition
In the United States, Christian J. Lambertsen developed oxygen rebreathing apparatus before and during World War II and coined the acronym SCUBA - Self-Contained Underwater Breathing Apparatus - for his Lambertsen Amphibious Respiratory Unit. His work was closely tied to military swimming and what would become U.S. special-operations diving.
Later U.S. research moved strongly into electronically monitored mixed-gas closed circuit. Systems such as the Biomarine CCR-1000 family and Carleton MK 15/MK 16 established an important military lineage for deep and specialized operations. The U.S. Navy’s MK 16 is a constant-PO2 mixed-gas CCR used for missions such as Special Warfare and mine countermeasures.
By the 1990s, the U.S. and British navies were among the world’s largest users of mixed-gas rebreathers, while only a small number of equivalent systems were in civilian technical-diving hands.
16.The Electronic Revolution - Krasberg and Walter Starck’s Electrolung
The development of reliable oxygen sensors in the 1960s made a major conceptual leap possible: instead of breathing a fixed premix, a machine could monitor the oxygen partial pressure in the loop and add oxygen as required.
Alan Krasberg is credited with important early electronic mixed-gas CCR work in the early 1960s. A few years later, marine scientist, inventor and underwater filmmaker Walter Starck introduced the Electrolung. Advertised to experienced sport and professional divers, the Electrolung was one of the first electronically controlled mixed-gas rebreathers offered outside purely military development channels.
The concept was revolutionary, but the technology was not yet mature enough for a mass sport market. Reliability problems, accidents, legal exposure and the limitations of contemporary electronics ended its commercial run. Nevertheless, the Electrolung demonstrated the architecture that would define modern eCCR diving: oxygen sensing, electronic control and dynamic mixed-gas management.
17.Why Civilian Rebreathers Nearly Disappeared from View
After Hans Hass and the early sport experiments, rebreathers did not immediately become the normal civilian scuba system. Open-circuit Aqua-Lung technology was cheaper, simpler, easier to teach and rapidly supported by a huge recreational industry. Rebreathers remained concentrated in military, commercial, scientific, police/rescue and specialist exploration communities.
There were also real access barriers. Some manufacturers restricted civilian sales, military mixed-gas technology remained sensitive during the Cold War, occupational diving was governed by national safety rules, and no universal recreational training or product standard existed. The commercial-diving industry evaluated CCRs but largely rejected them at the time because complexity and failure management outweighed gas savings for many operations.
It is sometimes remembered that a particular “law” preventing civilian rebreather use disappeared around 1995-96. We have not identified evidence for one universal European or German statute that simply banned civilian rebreathers and was repealed in 1996. What can be documented is a major regulatory and market transition: the Cold War had ended, sport nitrox was becoming mainstream, dedicated technical training organizations existed, and manufacturers were now willing to design, sell and support rebreathers expressly for recreational divers.
The Dräger Dolphin manual itself cites Germany’s Gerätesicherheitsgesetz - the Equipment Safety Act - and explicitly describes the Dolphin as equipment constructed for recreational diving, while requiring recognized rebreather training. That points to civilian product-safety regulation and training requirements rather than the removal of a blanket “rebreathers are illegal” rule.
18.Cave Divers Force Redundancy - Hasenmayer’s Speleo-Twin
Extreme cave diving created a different problem: a rebreather could provide extraordinary range, but a single life-support loop also created a single critical system. Long penetrations required redundancy that could remain efficient enough to carry through the cave.
German cave explorer Jochen Hasenmayer was one of the earliest pioneers of dual rebreather systems. In 1981 he used his home-built Speleo-Twin Rebreather, STR-80, while exploring the Émergence du Ressel. The twin closed-circuit concept gave him both extended range and a second breathing system - an idea that anticipated modern bailout-rebreather philosophy by decades.
19.Olivier Isler and Alain Ronjat - RI 2000 and the Dual/Triple Rebreather Cave Era
Another landmark came from Swiss/French cave exploration. Olivier Isler and engineer Alain Ronjat developed the RI 2000 semi-closed rebreather during the 1980s for long European cave penetrations. The design was intentionally redundant and evolved into dual and even triple-circuit configurations.
Isler used the RI 2000 in La Doux de Coly and other major systems, passing previous limits and demonstrating that very long cave dives could be undertaken with fully autonomous rebreather-based logistics. Later explorers such as Reinhard Buchaly and Michael Waldbrenner continued the approach with twin RB80 semi-closed rebreathers.
This European cave lineage is crucial to the modern frontmount, sidemount and bailout-rebreather story. The concept of carrying more than one breathing loop for extreme penetration is not a new fashion; it has deep roots in exploration history.
20.Bill Stone, Wakulla and the Cis-Lunar Revolution
In the United States, engineer and cave explorer Dr William “Bill” Stone pushed rebreather development in a different direction: highly integrated, computer-controlled exploration life support.
Stone’s early Cis-Lunar MK-1 - often associated with the acronym FRED, Fully Redundant Electronic Diver - was a landmark fully redundant electronic CCR. In December 1987 Stone completed a 24-hour underwater test dive with the MK-1, demonstrating the endurance and system redundancy required for exploration on a scale conventional scuba could not easily support.
The Wakulla Springs Project and the wider Wakulla karst-plain exploration program became a proving ground for this philosophy. It combined long-range cave penetration, propulsion vehicles, decompression habitats, sophisticated mapping and computer-controlled closed-circuit life support. The result looked less like ordinary scuba diving and more like an underwater expedition system.
It is important to phrase the milestone accurately: the Cis-Lunar MK-1 was not the first electronic rebreather ever - Krasberg and Starck had already demonstrated electronic mixed-gas concepts. Its significance was the integration of redundancy, electronics, expedition endurance and cave-exploration requirements into a sophisticated modern exploration CCR architecture.
21.From Exploration Prototype to Civilian Market - The Early 1990s
By the early 1990s, the ingredients for a civilian rebreather revival were finally converging. Technical diving was becoming an identifiable discipline. Nitrox and trimix were spreading. AquaCORPS and the emerging tek conferences were openly discussing equipment and procedures that had previously circulated mainly in military, commercial and small exploration circles.
The first Rebreather Forum in 1994 brought scientists, manufacturers, military specialists and technical divers together. It was followed by Rebreather Forum 2.0 in 1996. These meetings did not make rebreathers safe overnight, but they helped create the shared vocabulary, training philosophy and safety culture necessary for a sport market.
22.1995-1997 - Dräger Atlantis and Dolphin Bring SCR to Mainstream Recreational Diving
In 1995 Dräger introduced the Atlantis, a semi-closed nitrox rebreather specifically aimed at recreational divers. The importance of this move was enormous: a century-old respiratory-protection and military-diving manufacturer was now openly marketing a rebreather as sport-diving equipment.
By Rebreather Forum 2.0 in 1996, Dräger reported roughly 850 Atlantis units sold. The Japanese Grand Bleu Fieno was another recreational SCR. Dräger subsequently refined the Atlantis into the Dolphin, supported by formal manuals and unit-specific training through recognized agencies.
The Atlantis/Dolphin did not create rebreather diving, but it broke an important psychological and commercial barrier. Rebreathers were no longer seen only as secretive naval equipment, experimental cave machines or industrial life-support systems. A trained recreational diver could walk into the emerging market and buy a factory-produced rebreather intended for sport use.
23.1997 - The AP Inspiration and the Production Sport eCCR
The next decisive step was the AP Diving BUDDY Inspiration, introduced in 1997. It became the first widely distributed production electronic closed-circuit rebreather to establish a durable civilian sport and technical training ecosystem.
Its electronic oxygen control, relatively compact architecture and growing agency support made constant-PO2 CCR diving available to a much broader technical community. From this point onward, the modern civilian CCR era accelerated rapidly.
24.eCCR and mCCR - Two Control Philosophies
Electronically controlled CCRs use oxygen sensors, control electronics and typically a solenoid to maintain a selected oxygen partial pressure. Manually controlled CCRs place more of the oxygen-control task directly with the diver, often using a constant-flow orifice plus manual addition.
The difference became one of the enduring philosophical divides in rebreather design: automation and electronic redundancy on one side, mechanical simplicity and active diver control on the other. Both approaches can be highly capable; neither removes the requirement for disciplined monitoring and bailout planning.
25.Why Exploration Divers Adopted CCR
Open-circuit gas consumption rises dramatically with ambient pressure because every exhaled breath is discarded. A rebreather retains the inert gas and most unused oxygen in the loop. Oxygen supply is therefore tied far more closely to metabolic consumption than to depth.
For helium diving the benefit is even more striking: expensive helium is not thrown away with every breath. At extreme depth or long duration, this transforms expedition logistics. The rebreather does not make the dive simple - it changes which problems dominate the dive.
26.The Decompression Advantage
An open-circuit diver breathes fixed mixtures selected for specific depth ranges, changing gases during ascent. A CCR can maintain an approximately constant oxygen partial pressure through much of the profile, making the breathing mixture progressively adapt as ambient pressure changes.
This effectively provides a near-continuously optimized nitrox or trimix mixture and can improve decompression efficiency compared with an equivalent fixed-gas strategy, provided the system and decompression planning are functioning correctly.
27.Silence - From Combat Swimmer to Wildlife Filmmaker
Bubble-free or low-bubble operation connects two very different parts of rebreather history. For the combat swimmer it reduces visual and acoustic signature. For the scientist, photographer or filmmaker it allows quieter interaction with marine life.
Hans Hass exploited this quality for observation and filming decades before modern wildlife CCR diving became common. Today it remains one of the most immediately noticeable differences between open-circuit and closed-circuit diving.
28.The Machine Can Keep Breathing While the Gas Becomes Dangerous
The rebreather’s greatest strengths create its defining hazard. A breathing loop can continue to move gas comfortably even when that gas is physiologically unsafe.
Hypoxia, excessive oxygen partial pressure and carbon-dioxide breakthrough can all become life-threatening. The diver therefore cannot judge loop safety simply from the fact that breathing feels possible. Rebreather diving requires continuous awareness of oxygen status, scrubber condition, loop integrity, gas addition, work of breathing and a viable escape strategy.
29.Rebreather Forums and the Growth of a Safety Culture
As civilian use expanded, accident experience made it clear that engineering alone would not solve the safety problem. Training, checklists, oxygen-sensor management, scrubber practice, human factors, bailout planning and standardized failure responses became central topics.
Rebreather Forum 3 in 2012 and Rebreather Forum 4 in Malta in 2023 continued the process, bringing together manufacturers, researchers, educators and highly experienced divers. The community’s central question had evolved from “Can we make this work?” to “How can the complete diver-machine system be made reliably safer?”
30.Modern Backmount Rebreathers
Backmount remains the configuration most divers associate with CCR. The scrubber, cylinders and major life-support components sit behind the diver in the space traditionally occupied by scuba cylinders. This layout supports large scrubber capacity, integrated onboard oxygen and diluent, sophisticated electronics and efficient trim.
Backmount CCRs now cover a spectrum from relatively conservative recreational profiles to deep hypoxic-trimix expeditions.
31.Counterlung Evolution
Many systems use over-the-shoulder counterlungs because positioning the breathing volume close to lung centroid can provide favorable work of breathing. Others use back-mounted counterlungs to clear the chest and simplify the diver’s frontal profile.
Counterlung location is not merely ergonomic. Hydrostatic pressure differences relative to the diver’s lungs directly influence breathing resistance, making diver position and configuration part of the breathing machine itself.
32.Frontmount and Chest-Mounted Rebreathers
Compact chest/front-mounted rebreathers place the breathing unit across the diver’s torso rather than occupying the conventional back position. They can be used as primary systems, travel units, or modular rebreathers integrated with back-mounted gas.
The concept also connects directly to historical designs: many early oxygen rescue and military rebreathers were worn on the chest. Modern materials and loop design have revived the location for entirely different operational reasons.
33.Sidemount Rebreathers
Sidemount CCRs place the rebreather along the diver’s side, in a position broadly analogous to a sidemount cylinder. They offer special advantages in caves, wreck restrictions and expedition systems where equipment may need to be removed, passed through restrictions or combined with other life-support modules.
Some modern platforms are dedicated sidemount units; others are modular systems capable of backmount, sidemount or bailout roles.
34.Bailout Rebreathers - Modern Redundancy Meets Old Cave-Diving Ideas
Traditionally, a CCR diver escapes a failed loop by switching to open-circuit bailout. But for very deep or long penetrations, carrying enough open-circuit gas may become an enormous logistical burden.
A bailout rebreather provides a second independent breathing loop. What looks like a modern innovation has direct historical ancestors in Hasenmayer’s Speleo-Twin, Isler’s RI 2000 and later twin-RB80 cave configurations. Today compact chest and sidemount rebreathers make the concept more practical for a wider range of expedition divers.
35.The Modern Rebreather Ecosystem
Today the market includes electronic CCRs, manual CCRs, semi-closed systems, backmount, chest/frontmount and sidemount architectures, recreational-oriented systems, expedition systems and bailout rebreathers.
The direction of travel is not toward one universal machine. It is toward mission-specific and increasingly modular life-support architectures.
36.Recreational Rebreather Diving
Not every rebreather dive is an extreme expedition. At recreational depths, a rebreather can provide long duration, quieter interaction with marine life and warmer, more humid breathing gas than open circuit. These qualities made recreational SCRs attractive in the 1990s and continue to motivate modern recreational CCR programs.
The important distinction is that recreational depth does not turn a rebreather into simple equipment. The same loop physiology and failure modes still require appropriate training and discipline.
37.Technical, Scientific and Explorative Rebreather Diving
At the technical level, modern CCRs support normoxic and hypoxic trimix, staged decompression, deep wrecks, cave penetration, long-duration surveying, biological research, photography, cinematography and extreme exploration.
The machine becomes less a replacement for a scuba cylinder and more a personal life-support platform. That conceptual shift is essential to understanding both its capability and its risks.
38.From Fleuss to Today - A Condensed Historical Chain
- 1850s-1870s - Regenerative breathing concepts emerge for hostile atmospheres.
- 1878 - Henry Fleuss develops a practical self-contained oxygen rebreather.
- 1880 - Severn Tunnel operation demonstrates hose-free underwater working capability.
- 1904 onward - Dräger closed-circuit rescue apparatus becomes central to mine rescue; “Draegermen” enter the vocabulary.
- 1907-1910s - Dräger Tauchretter and Davis Submerged Escape Apparatus establish submarine escape rebreathers.
- 1914 onward - Proto oxygen rebreathers enter organized firefighting and rescue service.
- 1940-1942 - Hans Hass and Dräger adapt regenerative oxygen equipment for the free-swimming scientific/filming diver.
- World War II - Italian Maiale teams and other combat swimmers demonstrate the tactical value of silent oxygen rebreathers.
- 1950s - Ove Lund and Dräger develop the Leutnant Lund military oxygen rebreathers.
- 1960s - Oxygen sensors enable practical electronically monitored mixed-gas CCR concepts; Krasberg’s work is followed by Walter Starck’s Electrolung.
- 1969 onward - Dräger FGT mixed-gas semi-closed systems serve mine-clearance/EOD roles.
- 1970s onward - Dräger LAR combat-swimmer systems and Soviet/Russian IDA families become Cold-War military standards.
- 1981 - Jochen Hasenmayer uses the dual STR-80 Speleo-Twin in major cave exploration.
- 1987 - Bill Stone performs the 24-hour Cis-Lunar MK-1/FRED test, advancing redundant electronic expedition CCR design.
- 1989-1990s - Olivier Isler and Alain Ronjat’s RI 2000 demonstrates dual/triple redundant rebreather cave exploration.
- 1994 - First Rebreather Forum helps bring military, scientific and technical-diving knowledge into a common civilian discussion.
- 1995 - Dräger Atlantis and Grand Bleu Fieno place recreational SCRs on the public sport-diving market.
- 1996 - Rebreather Forum 2.0 documents rapidly growing civilian interest and the need for standardized training and safety practice.
- 1997 - AP Inspiration accelerates the modern production sport eCCR era.
- 2000s-2020s - CCR becomes established for deep wrecks, caves, scientific work and exploration; backmount, frontmount and sidemount architectures diversify.
39.And Yet the Central Principle Has Never Changed
The history of the rebreather is not simply a history of diving equipment. It is the history of one extremely powerful idea: instead of carrying and discarding enormous quantities of breathing gas, conserve the gas already present and replace only what the human body actually consumes.
That idea allowed a Victorian diver to travel farther into a flooded tunnel. It allowed mine rescuers and firefighters to work where the atmosphere itself could kill them. It gave submariners an escape system. It allowed combat swimmers to move silently beneath enemy harbours. It gave Hans Hass a quiet platform for scientific observation and filmmaking. It allowed Hasenmayer, Isler and Stone to rethink the limits of cave exploration. And today it supports dives ranging from quiet reef photography to some of the most demanding underwater expeditions ever attempted.
Breathe the gas. Remove the carbon dioxide. Replace the oxygen. Breathe it again.
Rebreathers Through Time 1878–2026
A chronological reference from the first practical oxygen rebreathers to modern CCRs.
This catalogue is the project master list: it preserves every rebreather/model family explicitly discussed in our article work and adds the important related systems uncovered during research. It is designed as an editorial/research framework, not as a claim that every experimental breathing apparatus ever built worldwide is known or represented.
Years are the best verified introduction/development dates currently available. “c.”, decade ranges and “era” labels are intentional where the historical record is uncertain, where several prototypes preceded production, or where a model family evolved over time.
Type guide: O2 CCR = pure-oxygen closed circuit; SCR = semi-closed; mCCR = manually/mechanically controlled CCR; eCCR = electronically controlled CCR; P-SCR/PVR-BASC = passive-addition semi-closed; BOB = bailout rebreather. Commercial helmet reclaim systems are included as a related branch of gas-recycling technology.
Catalogue entries: 236
| Year / period | Model / system | Manufacturer / origin | Function / type | Role / architecture | Remarks for article |
|---|---|---|---|---|---|
| 1878 | Fleuss apparatus | Henry A. Fleuss / Siebe Gorman (UK) | O2 CCR; one breathing bag; chemical CO2 absorption | Diving / technical | First practical self-contained closed-circuit oxygen breathing apparatus; foundational diving/rebreather milestone. |
| 1880 | Fleuss apparatus - Severn Tunnel use | Siebe Gorman / Alexander Lambert (UK) | O2 CCR; working diving apparatus | Diving / technical | Famous operational use in flooded Severn Tunnel; demonstrated hose-free penetration capability. |
| c.1906 | Garforth WEG apparatus | UK | O2 rescue rebreather | Rescue / escape | Early British rescue/industrial closed breathing apparatus; part of pre-scuba rescue lineage. |
| c.1906 | Meco-Briggs breathing apparatus | UK | O2 rescue rebreather | Rescue / escape | Early British industrial/rescue breathing apparatus. |
| c.1906 | Hall-Rees & Davis apparatus | UK | O2 rescue rebreather | Rescue / escape | Early British closed-circuit rescue apparatus. |
| c.1910 | Davis Submerged Escape Apparatus (DSEA) | Siebe Gorman / Robert Davis (UK) | O2 closed-circuit submarine escape apparatus | Rescue / escape | Major submarine-escape milestone; also influenced shallow diving apparatus. |
| c.1912 | Early Dräger diving/rebreathing sets | Dräger (Germany) | O2 CCR / rescue / diving apparatus | Rescue / escape | Early commercial Dräger closed-circuit equipment for rescue, escape and diving applications. |
| 1913-1918 | Dräger Selbstretter Tübben | Dräger / Ludwig Tübben (Germany) | Pendulum O2 rebreather; lung-operated addition | Diving / technical | One of the first mass-produced oxygen rebreathers; widely relevant to rescue history. |
| 1919-1920 | Dräger Versuchgeräte | Dräger (Germany) | Experimental O2 rebreathers | Diving / technical | Post-WWI experimental apparatus in Dräger development line. |
| c.1920s | Siebe Gorman Proto | Siebe Gorman (UK) | O2 rescue rebreather / SCBA | Rescue / escape | Very important mine rescue and later fire/rescue apparatus family. |
| c.1920s | Siebe Gorman Salvus / Salvus Special | Siebe Gorman (UK) | O2 rescue rebreather | Rescue / escape | Compact closed-circuit rescue apparatus. |
| c.1920s | Siebe Gorman Minox / Miniox | Siebe Gorman (UK) | O2 rescue rebreather | Rescue / escape | Industrial/fire/rescue closed-circuit apparatus family. |
| 1923 | Dräger Bergbau-Gerät Modell 1923 | Dräger (Germany) | O2 mine-rescue rebreather; breathing-operated O2 addition | Rescue / escape | Important mechanical demand-addition milestone. |
| 1924 | Dräger HSS Modell 1924 | Dräger (Germany) | O2 rescue rebreather; side-hose layout | Rescue / escape | Historic Dräger rescue system; representative of interwar breathing apparatus engineering. |
| 1930s | Dräger Gegenlunge / Tauchretter family | Dräger (Germany) | O2 closed-circuit escape / shallow diving apparatus | Rescue / escape | Important German submarine escape and breathing-apparatus lineage preceding Hass swimming systems. |
| interwar | Siebe Gorman Lungovox | Siebe Gorman (UK) | O2 rescue breathing apparatus | Rescue / escape | British rescue rebreather family. |
| interwar | Siebe Gorman Vitox | Siebe Gorman (UK) | O2 rescue apparatus | Rescue / escape | Historical British oxygen-breathing apparatus. |
| interwar | Aerophor / Aerorlox / Oxylet | Various European/UK | O2 rescue breathing apparatus | Rescue / escape | Representative early rescue rebreather names found in historical apparatus databases. |
| 1936 | Momsen Lung | U.S. Navy (USA) | Submarine escape rebreather | Military / professional | Iconic submarine escape device; historically often compared with Davis and Dräger apparatus. |
| early 1940s | Pirelli ARO 49 / 49 Bis / G50 | Pirelli (Italy) | O2 CCR; military combat-swimmer apparatus | Military / professional | Italian WWII oxygen rebreathers; part of combat-swimmer / human-torpedo history. |
| WWII | Italian Maiale / SLC breathing sets | Regia Marina / Italian suppliers | O2 CCR for human-torpedo combat swimmers | Military / professional | Used with Siluro a Lenta Corsa “Maiale” operations; major wartime rebreather milestone. |
| c.1941-1944 | Amphibian Mk I / Mk II | Siebe Gorman / Royal Navy (UK) | O2 CCR; combat swimmer | Military / professional | British wartime swimmer rebreather family. |
| 1942 | Hans Hass “Aegean 1942” apparatus | Hans Hass / modified Dräger components (Austria/Germany) | Simple O2 CCR; swimming-diver apparatus | Diving / technical | Early Hass bubble-free research/film system; name “Aegean 1942” is a later historical label, not original product name. |
| WWII | Mk II Human Torpedo Apparatus | Royal Navy / Siebe Gorman (UK) | O2 CCR; human torpedo | Military / professional | British wartime human-torpedo breathing apparatus. |
| WWII | Mine Recovery Suit / MRS apparatus | Royal Navy / Siebe Gorman (UK) | O2 CCR; mine recovery | Military / professional | Special-purpose military mine-recovery breathing apparatus. |
| WWII/postwar | Dunlop UWSBA | Dunlop / Royal Navy (UK) | O2 underwater swimming breathing apparatus | Military / professional | Experimental/early postwar military swimmer system. |
| 1940s | Cressi ARO 47 | Cressi (Italy) | O2 CCR | Diving / technical | Early Italian oxygen rebreather lineage, later followed by additional Cressi ARO models. |
| postwar | Amphibian Mk IIa shallow-water set | Siebe Gorman / Royal Navy | O2 CCR | Military / professional | Shallow-water swimmer variant in Amphibian family. |
| late 1940s-1950s | Cressi ARO 57B / Super ARO | Cressi (Italy) | O2 CCR | Diving / technical | Italian shallow oxygen rebreathers used in military/sport contexts. |
| postwar | Amphibian Mk IV Frogman | Siebe Gorman / Royal Navy | O2 CCR | Military / professional | Postwar British frogman oxygen rebreather. |
| late 1940s-1950s | Salvas oxygen rebreathers / Universal 971 lineage | Salvas (Italy) | O2 CCR | Diving / technical | Italian professional/military oxygen rebreather family. |
| postwar | CDBA / DSSCCD | Siebe Gorman / Royal Navy (UK) | Backmounted oxygen/mixed military diving apparatus | Military / professional | Clearance-diving family; significant British professional/military lineage. |
| 1950s | Mordem ARO | Mordem (Italy) | O2 CCR | Diving / technical | Italian oxygen rebreather; later seen in historical/surplus circles. |
| 1950s | Nautilus / Naubos AR88 / AR90 lineage | Nautilus (Italy) | O2 CCR | Diving / technical | Italian oxygen rebreather family represented in collector/surplus databases. |
| 1950s | Pirelli LS series (LS 701 / LS 901) | Pirelli (Italy) | O2 CCR; military/professional | Military / professional | Important Italian oxygen rebreather line; LS901 especially well documented. |
| 1950s | Submarine Products Oxymax-3 | Submarine Products (UK) | O2 CCR | Diving / technical | Compact British oxygen rebreather; later civilian/collector relevance. |
| 1950s | Kleintauchgerät 138 | Dräger / Hans Hass development lineage (Germany) | O2 CCR; compact swimming-diver set | Diving / technical | Important Hass/Dräger swimming-diver development; used for research, expeditions and filming. |
| 1950s | Siebe Gorman Novus / Proton | Siebe Gorman (UK) | Closed breathing apparatus for chamber/diving applications | Diving / technical | Specialized British closed-circuit system; Novus associated with submersible decompression chamber use. |
| 1950s | Seba / Stelox / Savox | Siebe Gorman / UK | O2 rescue rebreather family | Rescue / escape | Historical British closed-circuit apparatus represented in oxygen-rebreather databases. |
| 1953 | Barakuda Tümmler | Dräger / Barakuda (Germany) | Sport O2 CCR; manual addition | Sport / recreational | Notable early sport-diving oxygen rebreather. |
| 1950s | Oxygers 57 | GERS / Fenzy / La Spirotechnique (France) | O2 CCR; military swimmer | Military / professional | Key French military oxygen rebreather; important in postwar European development. |
| 1955/1957 | IDA-57 | USSR | O2 CCR; adjustable metering plus demand function | Homebuild / conversion | Russian military/escape/work apparatus; later valued as a donor by homebuilders. |
| 1950s-1960s | Walcher / Pneumatogen / Aerolith lineage | Austria/Central Europe | O2 rescue / regenerative breathing apparatus | Rescue / escape | Central-European rescue breathing heritage; relevant contextual branch rather than mainstream diving CCR. |
| 1950s | IDA-59 / IDA-59M | USSR | Military rebreather; O2/mixed configurations depending variant | Military / professional | Major Soviet apparatus; widely encountered later in surplus and conversion projects. |
| 1950s-1960s | Fenzy PO series / PO68 | Fenzy (France) | O2 CCR | Diving / technical | French military/professional oxygen rebreather family; PO68 commonly appears in historical collections. |
| late 1950s-1960s | NEMBA | Siebe Gorman for Dutch Navy (Netherlands/UK) | O2 military breathing apparatus | Military / professional | Nederlandse Marine Breathing Apparatus; Dutch naval oxygen set. |
| 1960s | Pirelli non-magnetic ARO | Pirelli (Italy) | O2 CCR; mine/EOD-oriented non-magnetic set | Military / professional | Compact non-magnetic military apparatus for work around underwater mines. |
| 1960s | Tecnoprene Combat | Tecnoprene (Italy) | O2 CCR; combat swimmer | Military / professional | Italian military oxygen rebreather line. |
| 1960s | Nemrod H-103 | Nemrod (Spain) | O2 CCR | Diving / technical | Spanish oxygen rebreather; noteworthy national lineage. |
| 1960s | EOBA | Tsuneyo Kaneko / Japan | O2 / closed breathing apparatus | Diving / technical | Japanese closed-circuit apparatus represented in historical databases. |
| 1960s-1980s | Polish W63P | Faser SA (Poland) | O2 industrial/mine-rescue rebreather | Rescue / escape | Polish industrial/rescue apparatus. |
| 1961 | Dräger LAR I | Dräger (Germany) | O2 CCR; combat swimmer | Military / professional | Beginning of the formal LAR military-swimmer series. |
| 1960s | Lambertsen Amphibious Respiratory Unit / LARU lineage | Christian Lambertsen (USA) | O2 CCR / military swimmer | Military / professional | Influential U.S. combat-swimmer rebreather lineage; Lambertsen also coined “SCUBA”. |
| 1960s | Emerson-Lambertsen rebreather | Emerson / Lambertsen (USA) | O2 CCR / military | Military / professional | U.S. development from Lambertsen concepts. |
| 1964 | Dräger LAR II | Dräger (Germany) | O2 CCR; combat swimmer | Military / professional | Second-generation LAR military oxygen rebreather. |
| 1960s | Dräger LAR IIc | Dräger (Germany) | O2 CCR; military | Military / professional | Variant in LAR development family. |
| 1960s | IDA-64 | USSR | O2 / military rebreather | Military / professional | Important Soviet military closed-circuit apparatus. |
| 1960s-1980s | Faser W70 / W70M | Faser SA (Poland) | O2 mine-rescue rebreather | Rescue / escape | Long-duration Polish rescue breathing apparatus family. |
| 1966 | Dräger LAR III | Dräger (Germany) | O2 CCR; military | Military / professional | Evolution of LAR swimmer apparatus. |
| 1966 | Dräger KAR I | Dräger (Germany) | O2 CCR / related military apparatus | Military / professional | Related German military closed-circuit development. |
| late 1960s | BioMarine CCR-1000 / CCR1000 | BioMarine Industries (USA) | eCCR; electronically controlled mixed-gas CCR | Diving / technical | Designed c.1969; civilian relative of Mk15 lineage; NEDU testing in 1970s. Important early eCCR. |
| 1968-1969 | Electrolung / Electrolung II | Walter Starck & John Kanwisher (USA/Australia) | eCCR; polarographic O2 sensors; electronic ppO2 control | Diving / technical | Major early electronic CCR milestone; three oxygen sensors and electronic control. |
| 1960s | ATE-1 | Poland | O2 tank-crew rescue set | Rescue / escape | Specialized Polish self-rescue apparatus. |
| 1969 | Dräger LAR IV | Dräger (Germany) | O2 CCR; military | Military / professional | LAR series development stage. |
| early 1970s | BioMarine Mk15 | BioMarine / U.S. military lineage (USA) | eCCR; mixed gas | Diving / technical | Foundational military/scientific electronic mixed-gas CCR; later film/exploration derivatives. |
| 1970s-1980s | Kirby Morgan / commercial helium-reclaim helmet systems | Kirby Morgan / offshore industry (USA) | Surface-supplied helmet gas recirculation/reclaim; CO2 scrubber | Commercial / offshore | Not self-contained CCR, but essential related branch: helium conservation in commercial deep diving. |
| 1970s-1990s | AU9L | Poland | O2 rebreather | Diving / technical | Polish oxygen apparatus. |
| 1970s-1990s | KA30 / KA60 | Poland | O2 self-rescue rebreather | Rescue / escape | Polish self-rescue closed breathing apparatus. |
| 1970s | BioMarine Mk15.5 | BioMarine (USA) | eCCR; mixed gas | Diving / technical | Prototype/hybrid Mk15/Mk16 lineage; famously used and heavily modified by Howard & Michele Hall for underwater cinematography. |
| 1970s | BioMarine Mk16 / U.S. Navy Mk16 | BioMarine / U.S. Navy (USA) | eCCR; constant-ppO2 mixed-gas military CCR | Military / professional | Major U.S. Navy EOD/special operations mixed-gas CCR lineage. |
| 1970s | IDA-71 / IDA-71U | USSR | Military rebreather; oxygen/chemical oxygen and mixed configurations by mode | Homebuild / conversion | One of the most famous Soviet surplus rebreathers; widely converted by civilian homebuilders in 1990s-2000s. |
| 1970s | IDA-72 / IDA-72V / IDA-72E | USSR | Military/industrial rebreather; heated variants | Military / professional | Large Soviet work/diving rebreather family; V hot-water and E electrically heated variants documented. |
| 1970s | IDA-73 | USSR | Heliox / deep-work rebreather derivative | Diving / technical | Developed from IDA-72E for heliox; relevant to Soviet deep/work diving history. |
| 1970s | KIP-8 | USSR | O2 firefighting/rescue rebreather | Homebuild / conversion | Widely available rescue apparatus; components later used by homebuilders. |
| 1975 | Dräger LAR V | Dräger (Germany) | Demand-added O2 CCR; combat swimmer | Military / professional | Iconic military oxygen rebreather; adopted in U.S. service as Mk25 lineage. |
| 1970s | U.S. Navy Mk25 / LAR V lineage | Dräger/U.S. Navy | O2 CCR; combat swimmer | Military / professional | U.S. military application of LAR V concept; demand oxygen addition. |
| 1970s | Oxygers 78 | France | O2 CCR | Diving / technical | French oxygen apparatus; distinct from mixed-gas Oxymixgers line. |
| 1978 | Oxymixgers 78 | La Spirotechnique / France | Hybrid: O2 closed circuit + Nitrox SCR | Diving / technical | French military hybrid system; predecessor to later mixed-gas military apparatus. |
| late 1970s | DC55 | La Spirotechnique / French Navy (France) | SCR / mixed-gas military rebreather | Military / professional | Famous French military semi-closed system; later seen in civilian technical/film circles. |
| 1970s-1980s | FROG / FROGS | France | O2 / military swimmer rebreather family | Military / professional | French combat-swimmer rebreather development line. |
| 1980s | CODE | France | Military oxygen/rebreather system | Military / professional | French military closed-breathing apparatus family. |
| c.1980 | Second Wind | Homebuilt / Fenzy-based | Manual CCR homebuild | Diving / technical | Very early documented homebuilt manual rebreather based on Fenzy hardware. |
| 1980s | Dräger LAR VI | Dräger (Germany) | O2 CCR / military | Homebuild / conversion | Later LAR generation; iconic shell/layout, imitated by homebuilders. |
| 1980s | Dräger LAR VII | Dräger (Germany) | Hybrid O2 CCR / Nitrox SCR military system | Military / professional | Dual-mode military rebreather; conceptually similar to French hybrid systems. |
| 1980s | SIEL / OMG Caimano early lineage | OMG/SIEL (Italy) | O2 CCR; combat swimmer | Military / professional | Italian modern military oxygen-rebreather family leading to later Mk2C/Mk3C/CRA. |
| 1983 | Arak M83 / Drina | Former Yugoslavia | O2 military rebreather | Military / professional | Yugoslav military oxygen unit; later donor for civilian mCCR conversions. |
| 1980s | Cis-Lunar Mk I / FRED | Dr. Bill Stone / Cis-Lunar (USA) | Computer-controlled eCCR; redundant exploration life-support | Exploration / technical | Development associated with Wakulla-era exploration; 24-hour testing and redundant architecture were major milestones. |
| mid-1980s | Divex Secondary Life Support (SLS) early series | Divex (UK) | Mechanical SCR bailout rebreather; commercial saturation diving | Commercial / offshore | Deep commercial/offshore bailout system designed in mid-1980s; led to SLS Mk IV and later COBRA. |
| 1980s-1990s | DIVEX mixed-gas bailout / SLS prototypes | Divex (UK) | Semi-closed commercial bailout rebreather | Commercial / offshore | Early commercial saturation bailout development preceding SLS Mk IV. |
| 1980s-2000s | Faser W2000 | Faser SA (Poland) | O2 rescue rebreather | Rescue / escape | Successor to W70 family. |
| 1980s | COMEX-PRO BOS / BOS II | COMEX / professional diving (France) | Commercial/offshore bailout rebreather | Commercial / offshore | Deep professional bailout rebreather lineage; important commercial-diving parallel to sport CCR development. |
| 1987 | Cis-Lunar FRED field era / Wakulla development | Dr. Bill Stone / Cis-Lunar | eCCR exploration platform | Exploration / technical | Key exploration milestone leading to increasingly sophisticated Cis-Lunar systems. |
| 1980s | Jochen Hasenmayer STR-80 / dual-rebreather concepts | Jochen Hasenmayer (Germany) | Redundant cave-exploration rebreather configuration | Exploration / technical | Early cave exploration use of redundant/double rebreather systems. |
| 1980s | Normalair-Garrett Deep Dive 55 / DD55 system | Normalair-Garrett (UK) | Professional deep-diving breathing system / helmet-based mixed-gas equipment | Commercial / offshore | Real professional deep-diving equipment seen in For Your Eyes Only; related to offshore heliox practice rather than a conventional sport CCR. |
| late 1980s-1990s | Olivier Isler / Alain Ronjat RI 2000 dual/triple systems | France/Switzerland exploration community | Redundant closed-circuit cave systems | Exploration / technical | Important European cave-exploration development; multiple independent loops/units for long penetrations. |
| c.1990 | OMG/SIEL Castoro P96 | OMG/SIEL (Italy) | O2 CCR; compact front/chest mount | Front / chest mount | Civilian/professional oxygen unit; important in Italian second-hand/surplus scene. |
| 1990s | Dräger LAR 5000 | Dräger (Germany) | Military oxygen/hybrid rebreather | Military / professional | Later LAR family evolution. |
| 1990s-current | Dräger FGT 5400 | Dräger (Germany) | Backmount professional/military rebreather; O2 closed-circuit and mixed mission modes | Military / professional | Important modern backmounted professional apparatus for EOD/underwater work; illustrates non-sport lineage. |
| 1990s | Dräger FGT series (early) | Dräger (Germany) | Mixed-gas / EOD / underwater-work rebreather | Military / professional | Professional/military mine-countermeasure and underwater-work family. |
| 1990s | Divex SLS Mk IV | Divex (UK) | SCR commercial bailout rebreather | Commercial / offshore | Deep saturation-diving secondary life support; backpack integrated with commercial helmet. |
| 1990s | Prism prototypes / PRISM Topaz lineage | Peter Ready (USA) | eCCR; digital mixed-gas CCR | Diving / technical | Peter Ready’s “Incredible Steam Machine”; influential independent technical CCR lineage. |
| 1994 | Rebreather Forum 1 era | Industry/community milestone | Civilian rebreather market/training milestone | Diving / technical | Not a unit; included as article milestone marking organized civilian rebreather discussion. |
| 1995 | Dräger Atlantis | Dräger (Germany) | Constant-flow Nitrox SCR | Diving / technical | Major purpose-built sport rebreather; key trigger of mid-1990s recreational market transition. |
| 1995 | Grand Bleu Fieno | Grand Bleu (Japan/France market) | Sport SCR | Sport / recreational | One of the very few purpose-built sport rebreathers around RF2 era. |
| 1995-1998 | Cis-Lunar Mk5 / Mk5P | Cis-Lunar Development Labs / Bill Stone (USA) | Advanced redundant eCCR / PLSS | Diving / technical | Commercialized exploration CCR; technologically advanced but expensive; key 1990s milestone. |
| 1996 | Dräger Dolphin | Dräger (Germany) | Constant-flow Nitrox SCR | Homebuild / conversion | Widely distributed recreational SCR; hugely influential in early sport rebreather training and later homebuild conversions. |
| 1996 | OMG/SIEL Castoro C96 / C96 Pro | OMG/SIEL (Italy) | O2 CCR; dual-hose, manual addition | Diving / technical | Italian civilian/professional oxygen rebreather; prominent in second-hand market. |
| mid-1990s | San-O-Sub P96 | San-O-Sub / OMG-derived (Italy) | Front-mounted O2 CCR; manual addition | Front / chest mount | Compact civilian oxygen rebreather derived from Italian OMG lineage. |
| 1997 | AP Buddy Inspiration / Inspiration Classic | Ambient Pressure Diving (UK) | eCCR; O2 + diluent; electronic solenoid control | Diving / technical | Defining mass-market civilian eCCR milestone; helped establish modern recreational/technical CCR training. |
| 1997 | OMG/SIEL Caimano Mk2C | OMG/SIEL (Italy) | O2 CCR; demand + manual bypass | Diving / technical | Civilian/military oxygen unit; second-hand/surplus relevance. |
| 1998 | Jetsam KISS Classic / KISS lineage | Jetsam Technologies / Gordon Smith (Canada) | mCCR; constant mass flow + manual O2 | Diving / technical | Foundational modern mCCR philosophy: simple, diver-controlled, mechanically assisted oxygen addition. |
| 1998 | OMG/SIEL Caimano Mk3C | OMG/SIEL (Italy) | O2 CCR | Diving / technical | Further Caimano combat-swimmer oxygen-rebreather development. |
| 1998 | Divex Stealth | Divex (UK) | Military mixed-gas rebreather | Military / professional | Royal Navy EOD/Special Forces system; developed from Divex commercial life-support experience. |
| late 1990s | Dräger Ray | Dräger (Germany) | Sport constant-flow Nitrox SCR | Sport / recreational | Simpler, compact recreational SCR; widely recognized late-1990s/early-2000s sport unit. |
| late 1990s | Buddy/Dräger-style SCR homebuild era | Various civilian builders | SCR conversions / donor-unit experimentation | Homebuild / conversion | Dolphin/Ray/Azimuth and military surplus became common donor platforms for early technical homebuilders. |
| 2000 | InnerSpace Megalodon | InnerSpace Systems Corp. (USA) | eCCR; modular technical CCR | Diving / technical | Major technical CCR milestone; long-lived modular platform with multiple controller generations. |
| 2000 | Halcyon RB80 | Halcyon (USA/Germany) | Passive-addition SCR (PVR-BASC) | Diving / technical | Highly influential cave/technical passive-addition rebreather; strong DIR/GUE historical association. |
| c.2000 | OMG/SIEL Caimano CRA / CMI | OMG/SIEL (Italy) | Military O2 CCR | Military / professional | Modern Italian military combat-swimmer oxygen system family. |
| c.2000 | Azimuth | OMG / San-O-Sub (Italy) | Active-addition SCR; radial scrubber; dual cylinders | Diving / technical | Popular European semi-closed unit; also became a donor for KISS-style mCCR conversions. |
| 2000s-current | Dräger LAR 7000 | Dräger (Germany) | Military oxygen/hybrid rebreather | Military / professional | Later LAR combat-swimmer generation. |
| early 2000s | Prism Topaz | Peter Ready / Steam Machines (USA) | eCCR; mixed gas | Diving / technical | Well-known technical eCCR prior to Hollis Prism 2 lineage. |
| c.2002 | rEvo prototypes / early rEvo | Paul Raymaekers / rEvo (Belgium) | mCCR/eCCR; dual scrubber architecture | Diving / technical | Distinctive dual-scrubber compact CCR, later offered in manual and electronic configurations. |
| early 2000s | Pelagian DCCCR | RebreatherLab / Andy Fritz (Thailand) | Diver-controlled CCR; needle-valve O2 feed | Diving / technical | Manual/mechanical CCR emphasizing simplicity and field serviceability. |
| 2003 | Submatix SCR 100 ST | Submatix / Uwe Lessmann (Germany) | Constant-flow SCR | Diving / technical | Beginning of broad Submatix commercial line; German recreational rebreather manufacturer. |
| 2003 | Submatix SCR 100 XT | Submatix (Germany) | Dual-gas SCR; adjustable needle-valve flows | Diving / technical | Underwater gas switching and adjustable flows; distinctive early Submatix model. |
| 2003-2005 | Submatix SCR 100 SMS | Submatix (Germany) | Self-mixing SCR / needle-valve system | Diving / technical | External oxygen supply and self-mixing concept within SCR100 family. |
| 2004 | M3S Triton CCR | M3S / later Aqualung-related market (France) | Front/chest-mount mCCR | Front / chest mount | One of the important early modern chest/front-mounted CCRs; remains conceptually influential. |
| 2004 | Hammerhead CCR / Hammerhead electronics era | Juergensen Marine (USA) | eCCR + integrated controller/decompression electronics | Diving / technical | Important controller and complete-CCR lineage; Hammerhead electronics also upgraded KISS, Inspiration, Mk15.5 and other units. |
| 2004 | Magnus Birkefeld Dolphin-Ray-LAR VI “The Dollar” | Magnus Birkefeld (Germany) | Homebuilt O2 CCR; LAR VI look-alike using Dräger Dolphin/Ray parts | Homebuild / conversion | Famous polished homebuild; original damaged LAR VI shell restored and fitted with Ray/Dolphin components. Published build story dated 2009. |
| c.1990s-2000s | William Sewell MR 101 | William Sewell | Homebuilt mCCR | Homebuild / conversion | Documented mCCR homebuild in TheRebreatherSite archive. |
| c.1990s-2000s | Steve Paige Scarab | Steve Paige | Homebuilt mCCR | Homebuild / conversion | Notable homebuilder project. |
| c.1990s-2000s | Stan Henning MCCR / HR-2 updates | Stan Henning | Homebuilt mCCR | Homebuild / conversion | Long-running homebuild/development work. |
| c.2000s | Roel Suk Dolphin MCCR | Roel Suk | Dolphin-to-mCCR conversion | Homebuild / conversion | Semi-closed Dräger Dolphin converted to manual CCR; stainless Hydrogom shell. |
| c.2000s | Richard Harris KISS-style rebreather | Richard Harris | Homebuilt KISS-style mCCR | Homebuild / conversion | Notable cave-diver homebuild; later famous for Thai cave rescue involvement. |
| c.2000s | Black Water Nymph | Uwe / homebuilder | CMF mCCR | Diving / technical | Built using East German/Russian parts. |
| c.2000s | Ralph Buscemi CCR | Ralph Buscemi | Homebuilt mCCR | Homebuild / conversion | Built from RG/UFM parts with homebuilt controllers. |
| c.2000s | Philippe Gerin KISS Azimuth | Philippe Gerin | Azimuth SCR-to-mCCR conversion | Homebuild / conversion | Converted OMG/San-O-Sub Azimuth to KISS-style CCR. |
| c.2000s | Paul Raymaekers IDA-71 MCCR | Paul Raymaekers | IDA-71 KISS-style mCCR conversion | Homebuild / conversion | Representative IDA-71 conversion with oxygen monitoring. |
| c.2000s | George Kamarinos Olive Green IDA | George Kamarinos | IDA-71 mCCR conversion | Homebuild / conversion | Another influential IDA-based civilian conversion. |
| c.2000s | Lothar Weidinger Black Russian IDA | Lothar Weidinger | IDA-71 + RG-UFM CMF mCCR | Diving / technical | Russian donor unit combined with constant-flow hardware. |
| c.2000s | Lothar Weidinger AKA60 + RG/UFM | Lothar Weidinger | MCCR conversion | Homebuild / conversion | Conversion of rare Russian semi-closed hardware to manual CMF CCR. |
| c.2000s | Joel Seymour IDA71 KISS | Joel Seymour | IDA-71 mCCR conversion | Homebuild / conversion | Russian surplus converted to KISS philosophy. |
| c.2000s | Jean Michel Urbani Dolphin KISS | Jean Michel Urbani | Dolphin-to-mCCR conversion | Homebuild / conversion | European homebuild conversion of Dräger SCR. |
| c.2000s | Ivan’s MCCR Dolphin | Ivan / homebuilder | Dolphin-to-KISS mCCR | Diving / technical | Semi-closed unit converted to manual closed circuit. |
| c.2000s | Lothar RG-IDA-UF71 | Lothar Weidinger | Hybrid donor-unit mCCR | Diving / technical | RG-UF/M and IDA parts combined into a single manual CCR. |
| c.2000s | Johan Duits Industrial Dolphin | Johan Duits | Dolphin mCCR conversion | Homebuild / conversion | New housing and reorganized oxygen injection. |
| c.2000s | Gabriele Paparo WC1 MCCR | Gabriele Paparo | Homebuilt mCCR | Homebuild / conversion | Documented homebuilder CCR. |
| c.2000s | Kerry McKenzie MK3 MCCR | Kerry McKenzie | Homebuilt mCCR | Homebuild / conversion | Documented homebuilder project. |
| c.2000s | Eric C. Cooper modified IDA-73 | Eric C. Cooper | IDA-73 mCCR conversion | Homebuild / conversion | Soviet donor unit adapted to civilian manual CCR. |
| c.2000s | Brent’s “Duck Tape Dolphin” | Brent / homebuilder | Dolphin conversion | Homebuild / conversion | Iconic improvised/experimental homebuild illustrating early conversion culture. |
| c.2000s | Ted Zarcone / Wayne Journey BioMarine 60 & 240 projects | Zarcone / Journey | Industrial BioMarine conversions | Homebuild / conversion | Industrial breathing apparatus adapted/experimented with for diving applications. |
| c.2000s | Andrew’s MCCR Dolphin | Homebuilder | Dolphin mCCR conversion | Homebuild / conversion | Another representative Dräger Dolphin conversion. |
| c.2000s | Matti Anttila IDA-59 conversion | Matti Anttila | IDA-59 conversion | Homebuild / conversion | Russian surplus donor conversion. |
| c.2000s | Alexey Stekolshikow IDA-72V recreational conversion | Alexey Stekolshikow | IDA-72V/IDA-59/KIP-8 hybrid SCR/mCCR project | Diving / technical | Complex Russian-donor project with custom CMF and homebuilt oxygen monitoring. |
| c.2000s | Valery Mukhin IDA-59SCR | Valery Mukhin | IDA-59M to SCR conversion | Homebuild / conversion | Documented Russian homebuild using Dolphin nozzle and external Nitrox supply. |
| c.2000s | Jan Bruggeman MCCR | Jan Bruggeman | Homebuilt mCCR | Homebuild / conversion | Documented homebuilder project. |
| c.2000s | Michel Biesmans “Le Joky” MCCR | Michel Biesmans | Homebuilt mCCR | Homebuild / conversion | European homebuilder project. |
| c.2000s | Åke Larsson Teknosofen Norge III MCCR | Åke Larsson | Norge-based mCCR conversion | Homebuild / conversion | Historic/military hardware adapted to manual CCR. |
| c.2000s | Kristiaan Slootmaeker Black Dolphin | Kristiaan Slootmaeker | Dolphin mCCR conversion | Homebuild / conversion | Homebuilt closed-circuit conversion. |
| c.2000s | Erik Ballast MCCR | Erik Ballast | Homebuilt mCCR | Homebuild / conversion | Documented homebuilder project. |
| c.2000s | Mike Eitel MeCCR | Mike Eitel | Homebuilt CCR | Homebuild / conversion | Independent homebuilt CCR project. |
| c.2000s | Mike Wescombe-Down CCRay | Mike Wescombe-Down | Dräger Ray mCCR conversion | Homebuild / conversion | Ray SCR converted toward manual CCR operation. |
| c.2000s | Tomas Stas Polish Rebreather | Tomas Stas | Homebuilt rebreather | Homebuild / conversion | Polish homebuilder project. |
| c.2000s | Frank Roeder Dark Side Dolphin v4.5 | Frank Roeder | Dolphin mCCR conversion | Homebuild / conversion | Developed homebuild version based on Dräger Dolphin. |
| c.2000s | Rajko M83 MCCR | Rajko / homebuilder | Arak M83 to mCCR conversion | Homebuild / conversion | Former Yugoslav military oxygen unit converted to mCCR. |
| c.2000s | X-ray | Alexey Konovalov | Dolphin/Ray-based mCCR rebuild | Diving / technical | Extensive redesign creating a new-looking manual CCR from donor parts. |
| c.2000s | Exive | Stefan Tietze | Double KISS-style homebuilt rebreather | Homebuild / conversion | Unique dual rebreather built for submarine-escape concept. |
| c.2000s | John Rosheuvel LAR oxygen rebreather | John Rosheuvel | Homebuilt O2 CCR | Homebuild / conversion | LAR-style oxygen rebreather using RG/UFM and homebuilt parts. |
| c.2000s | James Harvey NSN4240 | James Harvey | Fenzy conversion to O2 CCR | Homebuild / conversion | Rebuild of small 1984 Fenzy rescue apparatus into oxygen diving rebreather. |
| c.2000s | Simone Puzzolo oxygen rebreather | Simone Puzzolo | Homebuilt O2 CCR | Homebuild / conversion | Low-cost oxygen rebreather using ordinary backpack-style components. |
| c.2000s | Mike Down NU-Lar6 | Mike Down | Passive-addition oxygen rebreather | Homebuild / conversion | Australian homebuild inspired by LAR-type equipment. |
| c.2000s | Teoman Naskali T1 | Teoman Naskali | Homebuilt O2 CCR | Homebuild / conversion | Compact oxygen rebreather homebuild. |
| c.2000s | Jorge Yantorno Yaro-09 | Jorge Yantorno | CMF O2 CCR + manual bypass | Diving / technical | Homebuilt constant-mass-injection oxygen rebreather. |
| c.2000s | Baruku | James Lee (Singapore) | CMF O2 CCR | Diving / technical | Compact homebuilt oxygen rebreather. |
| c.2000s | GK Mk1 | GK / homebuilder | Manual oxygen CCR | Diving / technical | Simple, functional homebuilt oxygen rebreather. |
| c.2000s | Juha Haapajärvi Breathwise | Juha Haapajärvi | Homebuilt electronic/variable ppO2 CCR | Homebuild / conversion | Homebuild featuring both variable and fixed ppO2 electronics. |
| 2005 | Dive Rite O2ptima | Dive Rite (USA) | eCCR; initially Hammerhead electronics | Diving / technical | Major technical CCR; production began late 2005; later evolved to Shearwater/DiveCAN electronics. |
| 2005 | AP Evolution / Inspiration Evolution | AP Diving (UK) | eCCR; compact Inspiration-family evolution | Diving / technical | Smaller/lighter Inspiration-family CCR; later Vision electronics family became central. |
| 2005 | AP Inspiration Vision / Evolution Vision era | AP Diving (UK) | eCCR; integrated Vision controller/decompression | Diving / technical | Important step toward integrated controller, decompression and HUD architecture. |
| 2005 | VR Technology Ouroboros | VR Technology / Kevin Gurr (UK) | eCCR; high-end technical/exploration CCR | Exploration / technical | Sophisticated technical CCR; VR3 was the computer ecosystem, not the rebreather itself. |
| mid-2000s | Hammerhead KISS conversion / HH-KISS | Juergensen Marine + Jetsam / homebuilders | eCCR conversion of KISS platform | Homebuild / conversion | Representative of crossover between simple KISS mechanics and electronic controller/solenoid systems. |
| 2000s | Submatix CCR / eCCR development line | Submatix (Germany) | CCR/eCCR development | Diving / technical | Submatix expanded beyond SCR100 into CCR and later Quantum/sidemount platforms. |
| 2008 | VR Technology Sentinel | VR Technology / Kevin Gurr (UK) | eCCR; technical CCR | Diving / technical | Successor-era VR Technology CCR after Ouroboros; later VMS/Nammu/RedBare lineage references. |
| 2008 | VMS / Nammu / RedBare lineage | Vobster Marine Systems (UK) | eCCR | Diving / technical | Related technical CCR lineage associated with Sentinel-era development and later RedBare branding. |
| 2009 | rEvo III | rEvo (Belgium) | mCCR/eCCR; dual scrubbers | Diving / technical | Mature rEvo generation; manual CMF or electronic solenoid variants; compact technical platform. |
| late 2000s | AP Inspiration XPD | AP Diving (UK) | eCCR; extended-duration Inspiration family | Diving / technical | Large-capacity Inspiration-family technical CCR. |
| 2010 | JJ-CCR | JJ-CCR ApS (Denmark) | eCCR; technical backmount | Diving / technical | Major modern technical CCR; robust stainless-frame architecture and Shearwater ecosystem. |
| 2010 | Hollis PRISM / PRISM 2 lineage | Hollis / Peter Ready design (USA) | eCCR; technical backmount | Diving / technical | Commercial continuation/evolution of Peter Ready PRISM concepts; Prism 2 became widely used technical CCR. |
| 2011 | OSEL Apocalypse IV | Open Safety Equipment Ltd (UK) | eCCR / open electronics philosophy | Diving / technical | Technically ambitious CCR with open-development concepts and extensive monitoring philosophy. |
| 2011 | Submatix Quantum / Quantum EXP | Submatix (Germany) | CCR/eCCR; backmount | Diving / technical | Presented at Boot Düsseldorf 2011; later Quantum models continued in market and appear in RF4/2026 guides. |
| 2012 | Poseidon MkVI Discovery / SE7EN lineage | Poseidon (Sweden) | eCCR; recreational-oriented automated CCR | Sport / recreational | Important attempt to bring highly automated CCR operation into recreational diving; evolved into SE7EN/SE7EN+. |
| 2012 | SF2 Backmount | ScubaForce (Germany) | eCCR; back-mounted counterlungs | Diving / technical | Modern German technical CCR known for back-mounted counterlung architecture. |
| 2012 | SF2 Sidemount | ScubaForce (Germany) | Sidemount eCCR | Sidemount | One of the early production sidemount CCRs in modern cave-diving wave. |
| 2012 | KISS Sidekick | KISS Rebreathers (Canada) | Sidemount CCR / bailout rebreather | Sidemount | Early compact sidemount CCR used as primary or bailout rebreather. |
| 2013 | Hollis Explorer | Hollis (USA) | Recreational SCR / electronically managed semi-closed | Sport / recreational | Recreational-oriented rebreather designed as bridge from OC to rebreather diving; later discontinued. |
| 2014 | Divesoft Liberty | Divesoft (Czech Republic) | eCCR; redundant electronics | Diving / technical | Highly redundant modern technical CCR; later expanded into sidemount/frontmount configurations. |
| mid-2010s | AP Inspiration EVO | AP Diving (UK) | eCCR; compact modern Inspiration family | Diving / technical | Modern AP backmount model; part of current EVO/EVP/XPD family. |
| 2016 | iQsub XCCR | iQsub (Czech Republic) | eCCR; backmount | Diving / technical | Modern technical CCR with modular electronics and contemporary design. |
| 2016-2018 | JFD/DIVEX COBRA | JFD / Divex (UK) | Mechanical SCR bailout rebreather; saturation diving | Commercial / offshore | Compact Bailout Rebreathing Apparatus; up to ~45 min independent gas and very deep commercial rating; successor concept to SLS. |
| 2016 | SubGravity Defender | SubGravity (USA) | eCCR; backmount | Diving / technical | Modern technical CCR listed in RF4/InDepth market guides. |
| 2016 | Fathom MKIII CCR | Fathom Dive Systems (USA) | eCCR; backmount | Diving / technical | Technical CCR designed with strong human-factors/engineering emphasis; later MKV. |
| 2016 | KISS Sidewinder | KISS Rebreathers (Canada) | Sidemount mCCR; dual scrubbers | Sidemount | Highly influential cave/sidemount CCR; compact horizontal scrubber architecture. |
| mid-2010s | Lungfish Orca early generations | Lungfish | Backmount CCR | Diving / technical | Earlier Orca generations preceding current Orca V6. |
| late 2010s | Poseidon SE7EN+ | Poseidon (Sweden) | eCCR; automated recreational/technical | Sport / recreational | Updated Poseidon electronic CCR line with recreational-to-technical positioning. |
| 2018 | Divesoft Liberty Sidemount | Divesoft (Czech Republic) | Sidemount eCCR | Sidemount | Production sidemount version of Liberty architecture. |
| 2018 | Halcyon RBK | Halcyon | Sidemount passive-addition rebreather | Sidemount | Sidemount passive-addition technical/cave rebreather. |
| 2018 | Submatix SMS 200 | Submatix (Germany) | Sidemount CCR | Sidemount | Submatix sidemount line; appears in RF4/InDepth market timelines. |
| 2018 | Submatix Quantum (modern production generation) | Submatix (Germany) | Backmount CCR | Diving / technical | Later production Quantum generation listed in contemporary market guides. |
| late 2010s-current | Dräger LAR 8000 | Dräger (Germany) | O2 CCR + Nitrox SCR military system | Military / professional | Current advanced LAR family; preserves pure-O2 mode and supports semi-closed Nitrox operation. |
| late 2010s | Lungfish Orca V6 | Lungfish | Backmount CCR | Diving / technical | Current guide model. |
| 2019 | Mares Horizon | Mares (Italy) | SCR; recreational/extended range semi-closed | Sport / recreational | Modern electronically monitored semi-closed rebreather; significant return of SCR concept. |
| 2019 | Hollis Prism 2 (modern production listing) | Hollis (USA) | eCCR; backmount | Diving / technical | Current/mature production generation of Prism architecture in contemporary market guides. |
| 2020 | Dive Rite CHO2ptima / O2ptima CM | Dive Rite (USA) | Front/chest-mount eCCR | Front / chest mount | Major modern chestmount electronic CCR; modular use with backmount/sidemount gas configurations. |
| 2020 | Other Gravity T-REB | Other Gravity | Sidemount CCR | Sidemount | Modern sidemount rebreather listed in RF4 market overview. |
| 2020s | Fathom MKV / MK-series evolution | Fathom Dive Systems | Backmount eCCR | Diving / technical | Modern Fathom line emphasizing engineering, WOB and human factors. |
| early 2020s | S7CCR | S7CCR | Sidemount CCR | Sidemount | Contemporary sidemount CCR included in 2026 InDepth guide. |
| early 2020s | T-REB / Treb CCR | Treb / contemporary manufacturer | Sidemount CCR | Sidemount | Contemporary sidemount model represented in current market guides. |
| 2020s | Halcyon RBK | Halcyon | Sidemount passive-addition rebreather | Sidemount | Compact passive-addition sidemount architecture. |
| 2022 | GBM CCR / Generic Breathing Machine | Scubatron / Gregory Borodiansky (USA/Mexico cave community) | Front/chest-mount mCCR; needle-valve oxygen control | Front / chest mount | Modern compact mechanical chestmount CCR; roots in cave-diving prototypes around 2020. |
| 2022 | Fathom Gemini CCR | Fathom Dive Systems (USA) | Sidemount CCR | Sidemount | Modern sidemount technical CCR. |
| 2022 | Shark Rebreather | Shark / European development | Hybrid/eCCR backmount (hCCR in later guide) | Diving / technical | Contemporary innovative CCR; current guide identifies modern hybrid-control direction. |
| 2022 | Lungfish Orca | Lungfish (UK) | eCCR / backmount | Diving / technical | Modern technical CCR; current guide includes Orca V6. |
| 2022 | Scubatron GBM listed production era | Scubatron | Frontmount mCCR | Front / chest mount | RF4 table listed “GMB/GBM” frontmount in 2022; now better known as GBM CCR. |
| 2023-2024 | iQsub FLEX 2 | iQsub (Czech Republic) | Sidemount CCR | Sidemount | Modern modular sidemount CCR in current InDepth guide. |
| 2023-2024 | iQsub FX CCR | iQsub (Czech Republic) | Front/chest-mount CCR | Front / chest mount | Modern chest/front mount architecture; part of growing frontmount market. |
| 2023-2024 | KISS Sidewinder 2 | KISS Rebreathers | Sidemount mCCR | Sidemount | Second-generation Sidewinder; updated cave/sidemount mechanical CCR concept. |
| 2023-2024 | Fathom MKV | Fathom Dive Systems | eCCR; backmount | Diving / technical | Later generation of Fathom technical CCR line. |
| 2020s | AP Inspiration EVP | AP Diving | eCCR; backmount | Diving / technical | Current AP Inspiration family variant positioned between EVO and XPD. |
| 2020s | AP Inspiration XPD current generation | AP Diving | eCCR; extended-duration backmount | Diving / technical | Current large-capacity AP CCR generation. |
| 2024 | Halcyon Symbios CM | Halcyon (USA/Germany) | Front/chest-mount eCCR; integrated digital ecosystem | Front / chest mount | Major new chestmount CCR; highly integrated electronics, manual injection at first stage, modern diagnostics roadmap. |
| 2024-2025 | DiveTalk GO | DiveTalk / Mike Young design lineage (USA) | Front/chest-mount mCCR | Front / chest mount | Compact travel-oriented mechanical chestmount CCR; modern return to simple manual chestmount philosophy. |
| 2024-2025 | Akuana Gator X | Akuana | Front/chest-mount CCR | Front / chest mount | Contemporary frontmount unit in 2026 InDepth guide. |
| 2025 | Shark hCCR current generation | Shark Rebreather | Hybrid CCR | Diving / technical | Current guide highlights hybrid-control architecture as a contemporary development. |
| 2025-2026 | Lombardi Undersea RD1 | Lombardi Undersea | Backmount CCR | Diving / technical | Contemporary backmount unit in 2026 InDepth guide. |
| 2025-2026 | Submatix Quantum current listing | Submatix | Backmount CCR | Diving / technical | Still represented in 2026 market guide; long-running German manufacturer lineage. |
| 2025-2026 | Vobster Marine RedBare | Vobster Marine Systems | Backmount eCCR | Diving / technical | Current/legacy technical CCR listing derived from Sentinel/VMS lineage. |
Next: Understanding the Machine
Before examining individual models or advanced procedures, Part 2 should follow one breath through the complete loop: mouthpiece → exhalation hose → counterlung → scrubber → oxygen monitoring → gas addition → inhalation side → diver.
From there we can compare oxygen CCR, SCR, mCCR and eCCR operation; examine scrubbers, sensors, counterlungs, ADV and manual addition; and build toward failures, bailout, decompression, backmount/frontmount/sidemount architecture and modern exploration systems.
Historical Note on the “1996 Law” Question
A specific blanket law that prohibited ordinary civilians from owning or using diving rebreathers and was then repealed in 1996 has not been verified in the sources reviewed for this edition. There were genuine regulatory, military-security, manufacturer-access and training barriers, and these varied by country. The most defensible historical statement is that 1995-1997 was a market and regulatory transition period: major manufacturers began producing civilian sport units, recognized training agencies created formal programs, and rebreathers moved from specialist/military availability into a supported recreational product category. If a specific German, Austrian or European statute is later identified, this section should be updated with the exact law, date and jurisdiction.
Selected Sources & Further Reading
- Dräger company history and chronology - mine-rescue breathing apparatus and early Tauchretter development.
- German Patent and Trade Mark Office (DPMA), Bernhard Dräger biography - Model 1904 rescue apparatus, “Draegermen,” and 1907 submarine Tauchretter.
- London Fire Brigade Museum, “A brief history of our breathing apparatus” - Proto closed-circuit use by firefighters.
- Science Museum Group Collection - Siebe Gorman Proto mine-rescue rebreather.
- Hans Hass Institute / historical material summarized by The Rebreather Site - development of Dräger swimming-diver equipment and Kleintauchgerät 138.
- Helmut Knüfermann, Dräger/Leutnant Lund historical research, The Rebreather Site - Leutnant Lund I/II and Norwegian Navy development.
- Michael Menduno, Rebreather Forum 3 historical review - Hans Hass, Krasberg, Walter Starck/Electrolung, early military/commercial CCR development, civilian rebreather revival.
- Rebreather Forum 2.0 / RF3 historical proceedings - 1995 Atlantis, 1996 market status, military versus civilian mixed-gas rebreather use.
- Dräger FGT 5400 product documentation - contemporary MCM/EOD non-magnetic semi-closed/oxygen closed-circuit system.
- Dräger military diving product documentation - LAR family and modern tactical rebreathers.
- Diving and Hyperbaric Medicine 52(1), 2022 - history of dual rebreathers in extended-range cave diving, Hasenmayer STR-80 and Isler RI 2000.
- Olivier Isler, “Do it Redundant,” InDEPTH, 2025 - RI 2000 development and European cave-rebreather history.
- Bill Stone / Cis-Lunar historical material summarized in Mastering Rebreathers and cave-diving histories - MK-1/FRED 24-hour dive and Wakulla exploration context.
- Dräger Dolphin owner’s manual, 3rd edition, November 1997 - recreational designation, training requirement and reference to the German Gerätesicherheitsgesetz.
- Rebreather Forum 4 Proceedings, 2024 - modern rebreather market, engineering, human factors and safety consensus.
Educational & Safety Disclaimer
This article is a historical and educational overview. It is not a substitute for manufacturer documentation, formal unit-specific rebreather training, supervised practice, current standards, medical advice, operational procedures or a validated dive plan. Rebreathers are life-support equipment. Historical practices described here may be unsafe by modern standards and must not be copied as operating procedures.