Decompression sickness is a medical condition caused by dissolved gases emerging from solution as bubbles inside the body tissues during decompression. DCS most commonly occurs during or soon after a decompression ascent from underwater diving, but can also result from other causes of depressurisation, such as emerging from a caisson, decompression from saturation, flying in an unpressurised aircraft at high altitude, and extravehicular activity from spacecraft. DCS and arterial gas embolism are collectively referred to as decompression illness.
An electro-galvanic fuel cell is an electrochemical device which consumes a fuel to produce an electrical output by a chemical reaction. One form of electro-galvanic fuel cell based on the oxidation of lead is commonly used to measure the concentration of oxygen gas in underwater diving and medical breathing gases.
Diving medicine, also called undersea and hyperbaric medicine (UHB), is the diagnosis, treatment and prevention of conditions caused by humans entering the undersea environment. It includes the effects on the body of pressure on gases, the diagnosis and treatment of conditions caused by marine hazards and how relationships of a diver's fitness to dive affect a diver's safety. Diving medical practitioners are also expected to be competent in the examination of divers and potential divers to determine fitness to dive.
Scuba diving is a mode of underwater diving whereby divers use breathing equipment that is completely independent of a surface air supply, and therefore has a limited but variable endurance. The name scuba is an anacronym 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, a gas blend with a higher oxygen content, known as enriched air or nitrox, has become popular due to the reduced nitrogen intake during long or repetitive dives. Also, breathing gas diluted with helium may be used to reduce the likelihood and effects of nitrogen narcosis during deeper dives.
Rubicon Foundation, Inc. is a non-profit organization devoted to contributing to the interdependent dynamic between research, exploration, science and education. The foundation, started in 2002, is located in Durham, North Carolina and is primarily supported by donations and grants. Funding has included the Office of Naval Research from 2008 to 2010. Gibson, Dunn & Crutcher has provided pro bono services to assist in copyright searches and support.
Divers Alert Network (DAN) is a group of not-for-profit organizations dedicated to improving diving safety for all divers. It was founded in Durham, North Carolina, United States, in 1980 at Duke University providing 24/7 telephonic hot-line diving medical assistance. Since then the organization has expanded globally and now has independent regional organizations in North America, Europe, Japan, Asia-Pacific and Southern Africa.
Peter B. Bennett was the founder and a president and CEO of the Divers Alert Network (DAN), a non-profit organization devoted to assisting scuba divers in need. He was a professor of anesthesiology at Duke University Medical Center, and was the Senior Director of the Center for Hyperbaric Medicine and Environmental Physiology at Duke. Bennett is recognized as a leading authority on the effects of high pressure on human physiology.
Latent hypoxia is a condition where the oxygen content of the lungs and arterial blood is sufficient to maintain consciousness at a raised ambient pressure, but not when the pressure is reduced to normal atmospheric pressure. It usually occurs when a diver at depth has a lung gas and blood oxygen concentration that is sufficient to support consciousness at the pressure at that depth, but would be insufficient at surface pressure. This problem is associated with freediving blackout and the presence of hypoxic breathing gas mixtures in underwater breathing apparatus, particularly in diving rebreathers.
Capt. Edward Deforest Thalmann, USN (ret.) was an American hyperbaric medicine specialist who was principally responsible for developing the current United States Navy dive tables for mixed-gas diving, which are based on his eponymous Thalmann Algorithm (VVAL18). At the time of his death, Thalmann was serving as assistant medical director of the Divers Alert Network (DAN) and an assistant clinical professor in anesthesiology at Duke University's Center for Hyperbaric Medicine and Environmental Physiology.
The decompression of a diver is the reduction in ambient pressure experienced during ascent from depth. It is also the process of elimination of dissolved inert gases from the diver's body which accumulate during ascent, largely during pauses in the ascent known as decompression stops, and after surfacing, until the gas concentrations reach equilibrium. Divers breathing gas at ambient pressure need to ascend at a rate determined by their exposure to pressure and the breathing gas in use. A diver who only breathes gas at atmospheric pressure when free-diving or snorkelling will not usually need to decompress, Divers using an atmospheric diving suit do not need to decompress as they are never exposed to high ambient pressure.
Robert William Hamilton Jr., known as Bill, was an American physiologist known for his work in hyperbaric physiology.
Eugene Weston Hobbs II, known as Gene Hobbs is an American technical diver and founding board member of the non-profit Rubicon Foundation. Hobbs has served as medical officer for the Woodville Karst Plain Project since 2004 and was named the 2010 Divers Alert Network/ Rolex Diver of the year. Hobbs was a hyperbaric technologist and simulation coordinator at Duke Medical Center before taking a position as the Director of Simulation for the University of North Carolina School of Medicine and Clinical Instructor in the Department of Pediatrics. As of 2018, Hobbs is the business manager for the UNC Health Care Department of Neurosurgery.
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.
Richard Deimel Vann is an American academic and diver.
Diving safety is the aspect of underwater diving operations and activities concerned with the safety of the participants. The safety of underwater diving depends on four factors: the environment, the equipment, behaviour of the individual diver and performance of the dive team. The underwater environment can impose severe physical and psychological stress on a diver, and is mostly beyond the diver's control. Equipment is used to operate underwater for anything beyond very short periods, and the reliable function of some of the equipment is critical to even short-term survival. Other equipment allows the diver to operate in relative comfort and efficiency, or to remain healthy over the longer term. The performance of the individual diver depends on learned skills, many of which are not intuitive, and the performance of the team depends on competence, communication, attention and common goals.
Investigation of diving accidents includes investigations into the causes of reportable incidents in professional diving and recreational diving accidents, usually when there is a fatality or litigation for gross negligence.
The following index is provided as an overview of and topical guide to underwater diving:
