Open circuit scuba systems discharge the breathing gas into the environment as it is exhaled, and consist of one or more diving cylinders containing breathing gas at high pressure which is supplied to the diver through a diving regulator. (wikipedia.org)
In open-circuit demand scuba, the diver expels exhaled breathing gas to the environment, and each breath is delivered at ambient pressure, on demand, by a diving regulator, which reduces the pressure from the storage cylinder. (wikipedia.org)
Lambertsen's invention, for which he held several patents registered from 1940 to 1989, was a rebreather and is different from the open-circuit diving regulator and diving cylinder assemblies also commonly referred to as scuba. (wikipedia.org)
Diver6
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. (wikipedia.org)
The breathing gas is supplied through a demand valve when the diver reduces the pressure in the demand valve housing during inhalation. (wikipedia.org)
In rebreather scuba, the system recycles the exhaled gas, removes carbon dioxide, and compensates for the used oxygen before the diver is supplied with gas from the breathing circuit. (wikipedia.org)
This may be managed by diligent monitoring of remaining gas, adequate planning and provision of an emergency gas supply carried by the diver in a bailout cylinder or supplied by the diver's buddy, and the skills required to manage the gas sources during the emergency. (wikipedia.org)
If you pick up just about any diving text, medical reference, or even read DAN's protocol for what to do when DCI manifests in a diver, the first directive will be to administer 100% oxygen by demand mask and transport the patient to a recompression chamber. (tdisdi.com)
Unless you are dealing with extreme exposures and incomplete decompression, symptoms will usually not present while the diver is still underwater. (tdisdi.com)
Diver's3
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 exhaled unused oxygen, which is then recirculated, and oxygen added to make up the volume when necessary. (wikipedia.org)
By the mid-twentieth century, high pressure gas 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. (wikipedia.org)
Unlike other modes of diving, which rely either on breath-hold or on breathing gas supplied under pressure from the surface, scuba divers carry their own source of breathing gas, usually filtered compressed air, allowing them greater freedom of movement than with an air line or diver's umbilical and longer underwater endurance than breath-hold. (wikipedia.org)
Carbon dioxide1
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, the system giving a dive duration of up to about three hours. (wikipedia.org)
Scuba2
Other equipment needed for scuba diving includes a mask to improve underwater vision, exposure protection by means of a diving suit, ballast weights to overcome excess buoyancy, equipment to control buoyancy, and equipment related to the specific circumstances and purpose of the dive, which may include a snorkel when swimming on the surface, a cutting tool to manage entanglement, lights, a dive computer to monitor decompression status, and signalling devices. (wikipedia.org)
Closed circuit equipment was more easily adapted to scuba in the absence of reliable, portable, and economical high-pressure gas storage vessels. (wikipedia.org)
Open circuit1
The volume of gas used is reduced compared to that of open circuit, so a smaller cylinder or cylinders may be used for an equivalent dive duration. (wikipedia.org)