Gordon Smith (born Flin Flon, Manitoba, Canada 1950, died January 9, 2006) was an inventor, machinist and tool and die maker notable for inventing the KISS diving rebreather. [1]
Gordon Smith was trained as a tool and die maker at C. A. Norgren, Littleton, Colorado. He returned to Canada in 1975 and went to work for Comptec International Ltd., a two color molding company, in Vancouver, British Columbia. Gordon Smith spent fourteen years at Comptec and moved from the position of Mold Maker to become manager of the Tooling, Engineering, and R&D departments. During this period he was responsible for increasing the machine operator output by a factor of 6. He also helped move Comptec into the telecommunications business and developed production systems for assembly of telephones which are in use today by almost every major telephone manufacturer in the world. [2]
Gordon Smith left Comptec in 1989 to start Kiss Manufacturing. In the late 1990s he invented and began producing the KISS line of diving rebreathers under the Jetsam Technologies name.
Gordon's was an avid scuba diver in the Pacific Northwest, diving all around British Columbia in his boat "Ferrous". In the mid-nineties, technical diving became a movement which provided some background on some commercially available rebreathers - very expensive and challenging to obtain at the time. Gordon was interested in the nology, and also in simply not finding his dives limited by the size of his tanks (generally consuming two tanks for every regular divers one). As a self-taught man and being the owner of his own machine shop, he had the means and technical ability to begin exploring the design and construction of his own rebreathers. There were virtually no certification agencies that could address non-military rebreathers and certainly no clear path forward towards acceptance of their use in recreational diving. For example, few charters at the time had the ability or the experience to accommodate rebreather divers (often relying upon live boats following bubble streams and with a business model based upon dives lasting under one hour). However, because Gordon's initial aim was simply restricted to diving on his own boat with individuals of his choosing he was able to proceed with developing these experimental devices without the burden and limitations of (self) regulatory considerations.
The first attempt in 1998 was a novel approach, with a unique piston serving as counterlungs rather than the conventional flexible bags. The approach was intended to use tank pressure to compensate for the o-ring friction and inertia of the displacing water. Although the o-ring friction in air was acceptable, the model could not handle the inertia of the necessary water displacement. The prototype suffered from excessive work of breathing and did not pass test of surface breathing while submerged for even a few minutes. It got him started however, and nevertheless had the dubious description of "looking like R2D2 making love to an octopus" according to Gordon.
His next prototype was a semi-closed design again, but this time with more conventional flexible counterlungs. This worked very successfully, and was dove for many months. However, with the experience he gained with the semi-closed designs, he saw that the fully closed system was certainly feasible and much more desirable in terms of performance. He quickly decided upon the merit of including an oxygen sensor due to the risk of inadvertent hypoxia if required to exercise at the surface. One of his innovations early on was the bailout-integrated mouthpiece, switching immediately to diluent for short term open-circuit operation in an emergency or even just upon entering the water. He also incorporated a regulator to prevent negative loop pressure should the counterlungs become fully deflated upon descent.
Gordon devised his fully closed rebreather system in 1998. One of his key contributions was to realize that the formidable electronics engineering required to automate control of the loop partial pressure of oxygen was neither required nor necessarily the best way to minimise the risk of hypoxia or hyperoxia. Instead, a constant mass flow orifice injected oxygen continually at a rate slightly under the divers basal metabolic rate - requiring only periodic top-ups by the diver. This was the KISS principle, the philosophy by which the diver was counter-intuitively made safer by removing electronic protections. Specifically, design philosophy was that the knowledge that the diver was the one and only thing controlling the loop oxygen level meant that attention was required and would be applied. This avoided the human tendency to eventually neglect to monitor the machine-controlled process outputs, which work seamlessly until there is a failure or mistake (whether software bug, miscalibration or other issue) and then cause an accident. In practice, the constant mass flow of oxygen meant that partial pressures changed so slowly that this form of manual control was actually very feasible and only required checking every few minutes (more often during exercise and when close to the surface perhaps). He developed a successful prototype, initially using two oxygen sensors in two separate larger blocks. With the availability of miniature readouts, he advanced the design to use a triple oxygen sensor system in order to allow there to be a "voting ability" for which sensor was malfunctioning if there was an error in one. He continued to innovate, including at one time experimenting with a "hands-free" tongue-based oxygen injection system he wryly called the "snog valve". He then perfected the system over several years, building further prototype units that were test dived by friends Natasha Dickinson and Daniel Reinders. In time he came to see the potential for commercial sales of the system, and began Jetsam technologies. Over time, he would begin to explore also a smaller recreational-sized version of the KISS rebreather as well. He also pursued a pneumatic air booster system for rebreathers, whereby partially full standard scuba cylinders could be used to top-up the smaller rebreather cylinders without the need for a motorized compressor.
The KISS brand was continued after his death, and was eventually acquired by the Darkwater Group, which also owns XDEEP and SEAL Drysuits, in 2020, to develop the KISS Sidewinder rebreather into the KISS Sidewinder 2. [3]
A scuba set, originally just scuba, is any breathing apparatus that is entirely carried by an underwater diver and provides the diver with breathing gas at the ambient pressure. Scuba is an anacronym for self-contained underwater breathing apparatus. Although strictly speaking the scuba set is only the diving equipment that is required for providing breathing gas to the diver, general usage includes the harness or rigging by which it is carried and those accessories which are integral parts of the harness and breathing apparatus assembly, such as a jacket or wing style buoyancy compensator and instruments mounted in a combined housing with the pressure gauge. In the looser sense, scuba set has been used to refer to all the diving equipment used by the scuba diver, though this would more commonly and accurately be termed scuba equipment or scuba gear. Scuba is overwhelmingly the most common underwater breathing system used by recreational divers and is also used in professional diving when it provides advantages, usually of mobility and range, over surface-supplied diving systems and is allowed by the relevant legislation and code of practice.
Technical diving is scuba diving that exceeds the agency-specified limits of recreational diving for non-professional purposes. Technical diving may expose the diver to hazards beyond those normally associated with recreational diving, and to a greater risk of serious injury or death. Risk may be reduced via appropriate skills, knowledge, and experience. Risk can also be managed by using suitable equipment and procedures. The skills may be developed through specialized training and experience. The equipment involves breathing gases other than air or standard nitrox mixtures, and multiple gas sources.
A rebreather is a breathing apparatus that absorbs the carbon dioxide of a user's exhaled breath to permit the rebreathing (recycling) of the substantially unused oxygen content, and unused inert content when present, of each breath. Oxygen is added to replenish the amount metabolised by the user. This differs from open-circuit breathing apparatus, where the exhaled gas is discharged directly into the environment. The purpose is to extend the breathing endurance of a limited gas supply, while also eliminating the bubbles otherwise produced by an open circuit system. The latter advantage over other systems is useful for covert military operations by frogmen, as well as for undisturbed observation of underwater wildlife. A rebreather is generally understood to be a portable apparatus carried by the user. The same technology on a vehicle or non-mobile installation is more likely to be referred to as a life-support system.
The Soviet, later Russian IDA71 military and naval rebreather is an oxygen rebreather intended for use by naval and military divers including Russian commando frogmen. As supplied it is in a plain backpack harness with no buoyancy aid. The casing is pressed aluminium with a hinged cover. It has a small optional nitrox cylinder which can be clipped on its outside to convert it to nitrox mode. It contains one oxygen cylinder and two absorbent canisters. In the bottom of its casing is an empty space which is intended for an underwater communications set.
Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface breathing gas supply, and therefore has a limited but variable endurance. The name scuba is an acronym for "Self-Contained Underwater Breathing Apparatus" and was coined by Christian J. Lambertsen in a patent submitted in 1952. Scuba divers carry their own source of breathing gas, usually compressed air, affording them greater independence and movement than surface-supplied divers, and more time underwater than free divers. Although the use of compressed air is common, other gas blends are also used.
Dräger is a German company based in Lübeck which makes breathing and protection equipment, gas detection and analysis systems, and noninvasive patient monitoring technologies. Customers include hospitals, fire departments and diving companies.
Edward Francis Eldred was a pioneer of scuba diving in Australia. He invented Porpoise scuba gear.
Technical Diving International (TDI) claims to be the largest technical diving certification agency in the world, and one of the first agencies to offer mixed gas and rebreather training. TDI specializes in more advanced Scuba diving techniques, particularly diving with rebreathers and use of breathing gases such as trimix and heliox.
CUMA is a make of rebreather underwater breathing set designed and made in Canada for the Canadian Armed Forces by Fullerton Sherwood Engineering Ltd to replace the Royal Navy CDBA.
A bailout bottle (BoB) or, more formally, bailout cylinder is a scuba cylinder carried by an underwater diver for use as an emergency supply of breathing gas in the event of a primary gas supply failure. A bailout cylinder may be carried by a scuba diver in addition to the primary scuba set, or by a surface supplied diver using either free-flow or demand systems. The bailout gas is not intended for use during the dive except in an emergency, and would be considered a fully redundant breathing gas supply if used correctly. The term may refer to just the cylinder, or the bailout set or emergency gas supply (EGS), which is the cylinder with the gas delivery system attached. The bailout set or bailout system is the combination of the emergency gas cylinder with the gas delivery system to the diver, which includes a diving regulator with either a demand valve, a bailout block, or a bailout valve (BOV).
The Lambertsen Amphibious Respiratory Unit (LARU) is an early model of closed circuit oxygen rebreather used by military frogmen. Christian J. Lambertsen designed a series of them in the US in 1940 and in 1944.
Underwater breathing apparatus is equipment which allows the user to breathe underwater. The three major categories of ambient pressure underwater breathing apparatus are:
Scuba gas management is the aspect of scuba diving which includes the gas planning, blending, filling, analysing, marking, storage, and transportation of gas cylinders for a dive, the monitoring and switching of breathing gases during a dive, efficient and correct use of the gas, and the provision of emergency gas to another member of the dive team. The primary aim is to ensure that everyone has enough to breathe of a gas suitable for the current depth at all times, and is aware of the gas mixture in use and its effect on decompression obligations, nitrogen narcosis, and oxygen toxicity risk. Some of these functions may be delegated to others, such as the filling of cylinders, or transportation to the dive site, but others are the direct responsibility of the diver using the gas.
Rebreather diving is underwater diving using diving rebreathers, a class of underwater breathing apparatus which recirculate the breathing gas exhaled by the diver after replacing the oxygen used and removing the carbon dioxide metabolic product. Rebreather diving is practiced by recreational, military and scientific divers in applications where it has advantages over open circuit scuba, and surface supply of breathing gas is impracticable. The main advantages of rebreather diving are extended gas endurance, low noise levels, and lack of bubbles.
The Halcyon Passive, Variable Ratio-Biased Addition Semi-Closed rebreather is a unique design of semi-closed rebreather using a depth-compensated passive gas addition system. Passive addition implies that in steady state operation addition of fresh feed gas is a response to low volume of gas in the loop - the gas is injected when the top of the counterlung activates a demand type addition valve, which provides feed gas as long as the diver continues to inhale. The mechanism discharges gas to the environment in proportion to breathing volume to induce this gas feed.
The Halcyon RB80 is a non-depth-compensated passive addition semi-closed circuit rebreather of similar external dimensions to a standard AL80 scuba cylinder. It was originally developed by Reinhard Buchaly (RB) in 1996 for the cave exploration dives conducted by the European Karst Plain Project (EKPP).
The history of underwater diving starts with freediving as a widespread means of hunting and gathering, both for food and other valuable resources such as pearls and coral. By classical Greek and Roman times commercial applications such as sponge diving and marine salvage were established. Military diving also has a long history, going back at least as far as the Peloponnesian War, with recreational and sporting applications being a recent development. Technological development in ambient pressure diving started with stone weights (skandalopetra) for fast descent. In the 16th and 17th centuries diving bells became functionally useful when a renewable supply of air could be provided to the diver at depth, and progressed to surface-supplied diving helmets—in effect miniature diving bells covering the diver's head and supplied with compressed air by manually operated pumps—which were improved by attaching a waterproof suit to the helmet and in the early 19th century became the standard diving dress.
The history of scuba diving is closely linked with the history of the equipment. By the turn of the twentieth century, two basic architectures for underwater breathing apparatus had been pioneered; open-circuit surface supplied equipment where the diver's exhaled gas is vented directly into the water, and closed-circuit breathing apparatus where the diver's carbon dioxide is filtered from the exhaled breathing gas, which is then recirculated, and more gas added to replenish the oxygen content. Closed circuit equipment was more easily adapted to scuba in the absence of reliable, portable, and economical high pressure gas storage vessels. By the mid-twentieth century, high pressure cylinders were available and two systems for scuba had emerged: open-circuit scuba where the diver's exhaled breath is vented directly into the water, and closed-circuit scuba where the carbon dioxide is removed from the diver's exhaled breath which has oxygen added and is recirculated. Oxygen rebreathers are severely depth limited due to oxygen toxicity risk, which increases with depth, and the available systems for mixed gas rebreathers were fairly bulky and designed for use with diving helmets. The first commercially practical scuba rebreather was designed and built by the diving engineer Henry Fleuss in 1878, while working for Siebe Gorman in London. His self contained breathing apparatus consisted of a rubber mask connected to a breathing bag, with an estimated 50–60% oxygen supplied from a copper tank and carbon dioxide scrubbed by passing it through a bundle of rope yarn soaked in a solution of caustic potash. During the 1930s and all through World War II, the British, Italians and Germans developed and extensively used oxygen rebreathers to equip the first frogmen. In the U.S. Major Christian J. Lambertsen invented a free-swimming oxygen rebreather. In 1952 he patented a modification of his apparatus, this time named SCUBA, an acronym for "self-contained underwater breathing apparatus," which became the generic English word for autonomous breathing equipment for diving, and later for the activity using the equipment. After World War II, military frogmen continued to use rebreathers since they do not make bubbles which would give away the presence of the divers. The high percentage of oxygen used by these early rebreather systems limited the depth at which they could be used due to the risk of convulsions caused by acute oxygen toxicity.
The following outline is provided as an overview of and topical guide to underwater diving:
A Diving rebreather is an underwater breathing apparatus that absorbs the carbon dioxide of a diver's exhaled breath to permit the rebreathing (recycling) of the substantially unused oxygen content, and unused inert content when present, of each breath. Oxygen is added to replenish the amount metabolised by the diver. This differs from open-circuit breathing apparatus, where the exhaled gas is discharged directly into the environment. The purpose is to extend the breathing endurance of a limited gas supply, and, for covert military use by frogmen or observation of underwater life, to eliminate the bubbles produced by an open circuit system. A diving rebreather is generally understood to be a portable unit carried by the user, and is therefore a type of self-contained underwater breathing apparatus (scuba). A semi-closed rebreather carried by the diver may also be known as a gas extender. The same technology on a submersible or surface installation is more likely to be referred to as a life-support system.