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113-765: Drowning is a type of suffocation induced by the submersion of the mouth and nose in a liquid. Submersion injury refers to both drowning and near-miss incident. Most instances of fatal drowning occur alone or in situations where others present are either unaware of the victim's situation or unable to offer assistance. After successful resuscitation , drowning victims may experience breathing problems, confusion, or unconsciousness . Occasionally, victims may not begin experiencing these symptoms until several hours after they are rescued. An incident of drowning can also cause further complications for victims due to low body temperature , aspiration , or acute respiratory distress syndrome (respiratory failure from lung inflammation). Drowning

226-497: A Lost Art , stated: "Some divers have a lung capacity of 14 liters, which is about double the size for a typical adult male. They weren't born this way. ... They trained themselves to breathe in ways to profoundly affect their physical bodies." There is no requirement by law that free-divers are required to do freediving courses or get certified. Although, due to the risks, it is recommended to take lessons and get certified. The free-divers course contains three levels: theory studies,

339-611: A competitors’ ability to accurately use a speargun via a set of individual and team events conducted in a swimming pool using free diving or apnea technique. The sport was developed in France during the early 1980s and is currently practised mainly in Europe . It is known as Tir sur cible subaquatique in French and as Tiro al Blanco Subacuático in Spanish. Competitive freediving

452-425: A confined water sessions generally completed in a swimming pool, and open water sessions in the ocean or Reservoir. Training for freediving can take many forms, some of which can be performed on land. The University of Miami presents a scientific freediving class that was developed by Claire Paris , a marine scientist and freediver, the class is the first of its kind at the university. One training exercise

565-411: A death before submersion. Aspirated water that reaches the alveoli destroys the pulmonary surfactant , which causes pulmonary edema and decreased lung compliance, compromising oxygenation in affected parts of the lungs. This is associated with metabolic acidosis, secondary fluid, and electrolyte shifts. During alveolar fluid exchange, diatoms present in the water may pass through the alveolar wall into

678-423: A dozen more that are only practiced locally. All disciplines can be practiced by both men and women, and only CMAS currently separates records in fresh water from those at sea. The disciplines of AIDA can be done both in competition and as a record attempt, with the exception of variable weight and no limits, which are both solely for record attempts. For all AIDA depth disciplines, the depth the athlete will attempt

791-568: A foreign body: Freediving Besides the limits of breath-hold , immersion in water and exposure to high ambient pressure also have physiological effects that limit the depths and duration possible in freediving. Examples of freediving activities are traditional fishing techniques, competitive and non-competitive freediving, competitive and non-competitive spearfishing and freediving photography , synchronised swimming , underwater football , underwater rugby , underwater hockey , underwater target shooting and snorkeling . There are also

904-482: A good chance of recovery if attended to within minutes. More than 10% of drownings may involve laryngospasm , but the evidence suggests that it is not usually effective at preventing water from entering the trachea. The lack of water found in the lungs during autopsy does not necessarily mean there was no water at the time of drowning, as small amounts of freshwater are absorbed into the bloodstream. Hypercapnia and hypoxia both contribute to laryngeal relaxation, after which

1017-453: A hand over their nose and mouth, while using the other hand to push the victim's jaw up. The corpses had no visible injuries, and were supplied to medical schools for money. Compressive asphyxia (also called chest compression) is mechanically limiting expansion of the lungs by compressing the torso, preventing breathing. " Traumatic asphyxia " or "crush asphyxia" usually refers to compressive asphyxia resulting from being crushed or pinned under

1130-406: A hand, pillow, or a plastic bag. Smothering can be either partial or complete, where partial indicates that the person being smothered is able to inhale some air, although less than required. In a normal situation, smothering requires at least partial obstruction of both the nasal cavities and the mouth to lead to asphyxia. Smothering with the hands or chest is used in some combat sports to distract

1243-447: A helicopter. Less than 6% of people rescued by lifeguards need medical attention, and only 0.5% need CPR. The statistics worsen when rescues are made by bystanders. If lifeguards or paramedics are unable to be called, bystanders must rescue the drowning person. It can be done using vehicles that the victim can reach, as row-boats or even modern robots, when they navigate across the water. Asphyxia Asphyxia or asphyxiation

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1356-483: A large extent determines the survival and long term consequences of drowning, In the case of children, most survivors are found within 2 minutes of immersion, and most fatalities are found after 10 minutes or more. If water enters the airways of a conscious person, the person will try to cough up the water or swallow it, often inhaling more water involuntarily. When water enters the larynx or trachea, both conscious and unconscious people experience laryngospasm , in which

1469-429: A large weight or force, or in a crowd crush . An example of traumatic asphyxia is a person who jacks up a car to work on it from below, and is crushed by the vehicle when the jack fails. Constrictor snakes such as boa constrictors kill through slow compressive asphyxia, tightening their coils every time the prey breathes out rather than squeezing forcefully. In cases of an adult co-sleeping with an infant ("overlay"),

1582-417: A liquid to the point of being unable to breathe. If this is not followed by an exit to the surface, low oxygen levels and excess carbon dioxide in the blood trigger a neurological state of breathing emergency, which results in increased physical distress and occasional contractions of the vocal folds . Significant amounts of water usually only enter the lungs later in the process. While the word "drowning"

1695-419: A low oxygen atmosphere, or in a vacuum; environments where sufficiently oxygenated air is present, but cannot be adequately breathed because of air contamination such as excessive smoke. Other causes of oxygen deficiency include but are not limited to: Smothering is a mechanical obstruction of the flow of air from the environment into the mouth and/or nostrils, for instance, by covering the mouth and nose with

1808-406: A massive increase in blood pressure and cardiac strain leading to cardiac arrest , and panic ), another 50% die within 15 – 30 minutes from cold incapacitation (loss of use and control of limbs and hands for swimming or gripping, as the body 'protectively' shuts down the peripheral muscles of the limbs to protect its core), and exhaustion and unconsciousness cause drowning, claiming the rest within

1921-581: A newborn infant long enough to cause apparent harm. It results most commonly from a drop in maternal blood pressure or interference during delivery with blood flow to the infant's brain . This can occur as a result of inadequate circulation or perfusion , impaired respiratory effort, or inadequate ventilation . There has long been a scientific debate over whether newborn infants with asphyxia should be resuscitated with 100% oxygen or normal air. It has been demonstrated that high concentrations of oxygen lead to generation of oxygen free radicals , which have

2034-404: A possible cause of death if the body was recovered from a body of water, near a fluid that could plausibly have caused drowning, or found with the head immersed in a fluid. A medical diagnosis of death by drowning is generally made after other possible causes of death have been excluded by a complete autopsy and toxicology tests. Indications of drowning are unambiguous and may include bloody froth in

2147-410: A range of "competitive apnea " disciplines; in which competitors attempt to attain great depths, times, or distances on a single breath. Historically, the term free diving was also used to refer to scuba diving , due to the freedom of movement compared with surface supplied diving . In ancient times freediving without the aid of mechanical devices was the only possibility, with the exception of

2260-410: A reason for drowning or the clinical cause of death for those who drown in cold water. Upon submersion into cold water, remaining calm and preventing loss of body heat is paramount. While awaiting rescue, swimming or treading water should be limited to conserve energy, and the person should attempt to remove as much of the body from the water as possible; attaching oneself to a buoyant object can improve

2373-481: A recreational activity is widely practiced and differs significantly from scuba diving . Although there are potential risks to all freediving, it can be safely practiced using a wide range of skill levels from the average snorkeler to the professional freediver. Compared to scuba diving, freediving offers: Freshwater springs, often with excellent visibility, provide good freediving opportunities but with greater risks. Diving into spring caverns with restricted access to

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2486-466: A role in reperfusion injury after asphyxia. Research by Ola Didrik Saugstad and others led to new international guidelines on newborn resuscitation in 2010, recommending the use of normal air instead of 100% oxygen. Classifications of different forms of asphyxia vary among literature, with differences in defining the concept of mechanical asphyxia being the most obvious. In DiMaio and DiMaio's 2001 textbook on forensic pathology, mechanical asphyxia

2599-453: A serious injury or death. Many behavioral and physical factors are related to drowning: Population groups at risk in the US are the old and young. Some additional causes of drowning can also happen during freediving activities: Drowning is split into four stages: People who do not know how to swim can struggle on the surface of the water for only 20 to 60 seconds before being submerged. In

2712-571: A set of competition rules that are used by affiliated organisations. Synchronized swimming is a hybrid form of swimming , dance , and gymnastics , consisting of swimmers (either solos, duets, trios, combos, or teams) performing a synchronized routine of elaborate moves in the water, accompanied by music. Synchronized swimming demands advanced water skills, and requires great strength, endurance, flexibility, grace, artistry and precise timing, as well as exceptional breath control when upside down underwater. During lifts swimmers are not allowed to touch

2825-538: A similar mechanism are cave-ins , or when an individual is buried in sand, snow, dirt, or grain. In homicidal cases, the term burking is often ascribed to a killing method that involves simultaneous smothering and compression of the torso. The term "burking" comes from the method William Burke and William Hare used to kill their victims during the West Port murders . They killed the usually intoxicated victims by sitting on their chests and suffocating them by putting

2938-728: A similar time. A notable example of this occurred during the sinking of the Titanic , in which most people who entered the −2 °C (28 °F) water died within 15–30 minutes. [S]omething that almost no one in the maritime industry understands. That includes mariners [and] even many (most) rescue professionals: It is impossible to die from hypothermia in cold water unless you are wearing flotation, because without flotation – you won't live long enough to become hypothermic. Submersion into cold water can induce cardiac arrhythmias (abnormal heart rates) in healthy people, sometimes causing strong swimmers to drown. The physiological effects caused by

3051-542: A swimming pool. It originated from within the physical fitness training regime existing in German diving clubs during the early 1960s and has little in common with rugby football except for the name. It was recognised by the Confédération Mondiale des Activités Subaquatiques (CMAS) in 1978 and was first played as a world championship in 1980. Underwater target shooting is an underwater sport that tests

3164-471: A team during the routine. Figures are made up of a combination of skills and positions that often require control, strength, and flexibility. Swimmers are ranked individually for this part of the competition. The routine involves teamwork and synchronization. It is choreographed to music and often has a theme. Synchronized swimming is governed internationally by FINA (Fédération Internationale de Natation). Underwater hockey (also called octopush , mainly in

3277-448: A team of breath-hold safety divers who will descend in time to meet the competitor during their ascent, and monitor them for the rest of the ascent. They will intervene if necessary, typically by securing the competitor's airway and swimming them up to the surface. The first safety diver will meet the competitor at somewhere around 1/3 to 1/4 of the target depth, usually with a maximum of 30m. The second will meet them about 10m shallower, and

3390-446: A third will be on standby in case of an emergency. The work can be challenging as many dives are done in a day, so the team of safety divers is usually rotated to ensure that they are not overtasked. In case of a deeper incident, the competitor is clipped to the downline for the duration of the dive, which can be rapidly raised by the surface support team, which includes a medical support group. The best official result in static apnea

3503-456: A toy rubber torpedo as the ball, and weighing down buckets to rest on the bottom and serve as goals. It is played in the Canadian provinces of Alberta , Manitoba , Newfoundland and Labrador , and Saskatchewan . Underwater rugby is an underwater team sport. During a match, two teams try to score a negatively buoyant ball (filled with saltwater) into the opponents’ goal at the bottom of

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3616-446: A weight of approximately 450 kg or 1000 lbs). In cases where people have stacked up on each other in a human pile, it has been estimated that those at the bottom are subjected to around 380 kg (840 lbs) of compressive weight. "Positional" or "restraint" asphyxia is when a person is restrained and left alone prone, such as in a police vehicle, and is unable to reposition themself in order to breathe. The death can be in

3729-569: Is a condition of deficient supply of oxygen to the body which arises from abnormal breathing . Asphyxia causes generalized hypoxia , which affects all the tissues and organs, some more rapidly than others. There are many circumstances that can induce asphyxia, all of which are characterized by the inability of a person to acquire sufficient oxygen through breathing for an extended period of time. Asphyxia can cause coma or death. In 2015, about 9.8 million cases of unintentional suffocation occurred which resulted in 35,600 deaths. The word asphyxia

3842-461: Is a specific hazard of deeper freedives. This effect can cause hypoxic blackout during surfacing. There is also a wide range of environmental hazards possible specific to the site and water and weather conditions at the time of diving, and there may be other hazards specific to the freediving activity. Failing to respond to physiological warning signals, or crossing the mental barrier by strong will, may lead to blackout underwater or on reaching

3955-431: Is allocated to enhance blood and muscle oxygen stores, to a limited extent. Most divers rely on increasing fitness by increasing CO 2 tolerance and lung capacity. Simple breath-holding practice is highly effective for the build-up of tolerance to CO 2 and to some degree increased lung capacity. In an interview on the radio talk show Fresh Air , journalist James Nestor, author of the book Breath: The New Science of

4068-427: Is an underwater sport where two competitors wearing masks and fins wrestle underwater in an attempt to remove a ribbon from each other's ankle band in order to win the bout. The "combat" takes place in a 5-metre (16 ft) square ring within a swimming pool, and is made up of three 30-second rounds, with a fourth round played in the event of a tie. The sport originated during the 1980s in the former USSR (now Russia) and

4181-449: Is announced before the dive; this is accepted practice for both competition and record attempts. Most divers choose monofin (MF) over bifins (BF) where there is a choice. Following the deaths of two freedivers in competitions, AIDA has a system set up for monitoring and if necessary, recovering competitors who lose consciousness underwater. As of 2022 the incidence of adverse events in depth competitions varies between 3 and 4%. This rate

4294-529: Is attributed to positional asphyxia. Therefore, passive deaths following custody restraint that are presumed to be the result of positional asphyxia may actually be examples of asphyxia occurring during the restraint process. Chest compression is a technique used in various grappling combat sports, where it is sometimes called wringing, either to tire the opponent or as complementary or distractive moves in combination with pinning holds , or sometimes even as submission holds . Examples of chest compression include

4407-691: Is automatic and allows both a conscious and an unconscious person to survive longer without oxygen underwater than in a comparable situation on dry land. The exact mechanism for this effect has been debated and may be a result of brain cooling similar to the protective effects seen in people who are treated with deep hypothermia . The actual cause of death in cold or very cold water is usually lethal bodily reactions to increased heat loss and to freezing water, rather than any loss of core body temperature. Of those who die after plunging into freezing seas, around 20% die within 2 minutes from cold shock (uncontrolled rapid breathing and gasping causing water inhalation,

4520-573: Is caused by pressure from outside the body restricting respiration. Similar narrow definitions of mechanical asphyxia have occurred in Azmak's 2006 literature review of asphyxial deaths and Oehmichen and Auer's 2005 book on forensic neuropathology. According to DiMaio and DiMaio, mechanical asphyxia encompasses positional asphyxia, traumatic asphyxia, and "human pile" deaths. In Shkrum and Ramsay's 2007 textbook on forensic pathology, mechanical asphyxia occurs when any mechanical means cause interference with

4633-792: Is commonly associated with fatal results, drowning may be classified into three different types: drowning that results in death, drowning that results in long-lasting health problems, and drowning that results in no health complications. Sometimes the term "near-drowning" is used in the latter cases. Among children who survive, health problems occur in about 7.5% of cases. Steps to prevent drowning include teaching children and adults to swim and to recognise unsafe water conditions, never swimming alone, use of personal flotation devices on boats and when swimming in unfavourable conditions, limiting or removing access to water (such as with fencing of swimming pools), and exercising appropriate supervision. Treatment of victims who are not breathing should begin with opening

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4746-460: Is considered relatively low and is expected during competitions where divers push their breath-hold limits. Almost all of these divers are successfully assisted and recover completely. There is a much lower incidence of more serious injuries. The safety team is usually made up of volunteers, or paid staff in some major events, and is supervised by the Chief of Safety . Each competitor is monitored by

4859-429: Is currently governed by two world associations: AIDA International and Confédération Mondiale des Activités Subaquatiques (CMAS). Historically, there were two more organisations that regulated freediving records and activities — International Association of Freedivers (IAFD) and Freediving Regulations and Education Entity (FREE). Each organization has its own rules on recognizing a record attempt which can be found on

4972-419: Is from Ancient Greek α- "without" and σφύξις sphyxis , "squeeze" (throb of heart). Situations that can cause asphyxia include but are not limited to: airway obstruction , the constriction or obstruction of airways, such as from asthma , laryngospasm , or simple blockage from the presence of foreign materials; from being in environments where oxygen is not readily accessible: such as underwater, in

5085-735: Is illegal in some countries. The use of mechanically powered spearguns is also outlawed in some countries and jurisdictions. Spearfishing is highly selective, normally uses no bait and has limited by-catch . Various cultures have collected shellfish by freediving for "possibly thousands" of years. One example is the historical recreational collection of abalone in South Africa, before illegal harvesting reduced stocks to levels which resulted in recreational collection being banned indefinitely. This did not completely stop illegal harvesting, because selling illegally harvested abalone remained lucrative. Aquathlon (also known as underwater wrestling)

5198-465: Is more likely to happen when spending extended periods of time near large bodies of water. Risk factors for drowning include alcohol use, drug use, epilepsy , minimal swim training or a complete lack of training, and, in the case of children, a lack of supervision. Common drowning locations include natural and man-made bodies of water, bathtubs , and swimming pools . Drowning occurs when a person spends too much time with their nose and mouth submerged in

5311-421: Is much greater in drowning than from other origins. Lung density may be higher than normal, but normal weights are possible after cardiac arrest or vasovagal reflex. The lungs may be overinflated and waterlogged, filling the thoracic cavity. The surface may have a marbled appearance, with darker areas associated with collapsed alveoli interspersed with paler aerated areas. Fluid trapped in the lower airways may block

5424-414: Is played in a swimming pool with snorkeling equipment ( mask , snorkel , and fins ). The goal of the game is to manoeuvre (by carrying and passing ) a slightly negatively buoyant ball from one side of a pool to the other by players who are completely submerged underwater . Scoring is achieved by placing the ball (under control) in the gutter on the side of the pool. Variations include using

5537-412: Is possible, they should assist from a safe ground position, such as a boat, a pier, or any patch of land near the victim. The fastest way to assist is to throw a buoyant object (such as a lifebuoy or a broad branch). It is very important to avoid aiming directly at the victim, since even the lightest lifebuoys weight over 2 kilograms, and can stun, injure or even render a person unconscious if they impact on

5650-436: Is short-lived. Submerging the face in water cooler than about 21 °C (70 °F) triggers the diving reflex , common to air-breathing vertebrates, especially marine mammals such as whales and seals . This reflex protects the body by putting it into energy-saving mode to maximise the time it can stay underwater. The strength of this reflex is greater in colder water and has three principal effects: The reflex action

5763-432: Is significantly shorter than that in air due to the cold shock response . The breath-hold breakpoint can be suppressed or delayed, either intentionally or unintentionally. Hyperventilation before any dive, deep or shallow, flushes out carbon dioxide in the blood resulting in a dive commencing with an abnormally low carbon dioxide level: a potentially dangerous condition known as hypocapnia . The level of carbon dioxide in

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5876-488: Is the Guinness WR of 11:54 by Branko Petrović in 2014, a freediver who has results over 10 minutes under both AIDA and CMAS. The best no limits result is 253.2m by Herbert Nitsch in 2012; his intention of having the dive sanctioned by AIDA fell through due to a sponsoring conflict. After 2001, AIDA International no longer separated the records achieved in fresh water from those in the sea. As of 1 January 2024 ,

5989-459: Is the apnea walk. This consists of a preparation "breathe-up", followed by a short (typically 1 minute) breath hold taken at rest. Without breaking the hold, participants then begin walking as far as possible until it becomes necessary to breathe again. Athletes can do close to 400 meters in training this way. This form of training is good for accustoming muscles to work under anaerobic conditions, and for tolerance to carbon dioxide build-up in

6102-453: Is theorized that other isolated diving populations globally may have experienced the same selection. Breath-holding ability, and hence dive performance, is a function of on-board oxygen stores, scope for metabolic rate reduction, efficient oxygen utilization, and hypoxia tolerance. Athletes attempt to accomplish this in various ways. Some divers use "packing", which increases lung volume beyond normal total lung capacity. In addition, training

6215-400: Is therefore lost quickly in water compared to air, even in 'cool' swimming waters around 70 °F (~20 °C). A water temperature of 10 °C (50 °F) can lead to death in as little as one hour, and water temperatures hovering at freezing can lead to death in as little as 15 minutes. This is because cold water can have other lethal effects on the body. Hence, hypothermia is not usually

6328-462: The CMAS recognized world records are: The AIDA recognized world records are: The following table only includes those disciplines that are modifications of existing AIDA or CMAS disciplines and Guinness-exclusive (as it recognizes and inherits some AIDA/CMAS records) or Guinness-conceived (CMAS and AIDA do/did sanction at some time) disciplines. As of 25 February 2018 : Freediving as

6441-814: The Hillsborough disaster in 1989, where 97 Liverpool fans were crushed to death in an overcrowded terrace, 95 of the 97 from compressive asphyxia, 93 dying directly from it and 3 others from related complications; the 2021 Meron crowd crush where 45 died; the Astroworld Festival crowd crush in 2021, where 10 died; and the Seoul Halloween crowd crush in 2022, where at least 159 died during Halloween celebrations. In confined spaces, people are forced to push against each other; evidence from bent steel railings in several fatal crowd accidents has shown horizontal forces over 4500 N (equivalent to

6554-624: The Ohio , Tennessee , and Mississippi , while others dived for marine pearls from the Caribbean and waters along the coasts of Central and South America . In 1940, Dottie Frazier pioneered freediving for women in the United States and also began teaching classes. It was also during this time that she began to design and sell rubber suits for Navy UDT divers. Spearfishing is an ancient method of fishing that has been used throughout

6667-548: The Peloponnesian War , divers were used to get past enemy blockades to relay messages as well as supplies to allies or troops that were cut off, and in 332 BC, during the Siege of Tyre , the city used divers to cut the anchor cables of Alexander 's attacking ships. In Japan, ama divers began to collect pearls about 2,000 years ago. For thousands of years, most seawater pearls were retrieved by divers working in

6780-638: The Sulu Archipelago . At times, the largest pearls belonged by law to the sultan, and selling them could result in the death penalty for the seller. Nonetheless, many pearls made it out of the archipelago by stealth, ending up in the possession of the wealthiest families in Europe. Pearling was popular in Qatar, Bahrain, Japan, and India. The Gulf of Mexico was also known for pearling. Native Americans harvested freshwater pearls from lakes and rivers like

6893-560: The United Kingdom ) is a globally played limited- contact sport in which two teams compete to manoeuvre a hockey puck across the bottom of a swimming pool into the opposing team's goal by propelling it with a hockey stick . The sport originated in England in 1954 when Alan Blake, the founder of the newly formed Southsea Sub-Aqua Club, invented the game he called octopush to keep the club's members interested and active during

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7006-467: The knee-on-stomach position ; or techniques such as leg scissors (also referred to as body scissors and in budō referred to as do-jime ; 胴絞, "trunk strangle" or "body triangle") where a participant wraps his or her legs around the opponent's midsection and squeezes them together. Pressing is a form of torture or execution using compressive asphyxia. Perinatal asphyxia is the medical condition resulting from deprivation of oxygen ( hypoxia ) to

7119-407: The larynx , and water can then enter the lungs, causing a "wet drowning". However, about 7–10% of people maintain this seal until cardiac arrest . This has been called " dry drowning ", as no water enters the lungs. In forensic pathology , water in the lungs indicates that the person was still alive at the point of submersion. An absence of water in the lungs may be either a dry drowning or indicates

7232-420: The lungs . Even small quantities can cause the extrusion of liquid into the lungs ( pulmonary edema ) over the following hours; this reduces the ability to exchange the air and can lead to a person "drowning in their own body fluid". Vomit and certain poisonous vapors or gases (as in chemical warfare ) can have a similar effect. The reaction can take place up to 72 hours after the initial incident and may lead to

7345-474: The mammalian diving reflex . The adaptations include: In addition to general adaptations within the human species , Freediving is an example of an activity that has been directly affected by recent human evolution . The Bajau , or “Sea Nomads,” have engaged in Freediving for thousands of years, and natural selection has led to larger spleen sizes. This serves as an oxygen reservoir when diving. It

7458-412: The vocal cords constrict, sealing the airway . This prevents water from entering the lungs . Because of this laryngospasm, in the initial phase of drowning, water enters the stomach, and very little water enters the lungs. Though laryngospasm prevents water from entering the lungs, it also interferes with breathing. In most people, the laryngospasm relaxes sometime after unconsciousness due to hypoxia in

7571-771: The Indian Ocean, in areas such as the Persian Gulf , the Red Sea , and in the Gulf of Mannar (between Sri Lanka and India ). A fragment of Isidore of Charax 's Parthian itinerary was preserved in Athenaeus 's 3rd-century Sophists at Dinner , recording freediving for pearls around an island in the Persian Gulf . Pearl divers near the Philippines were also successful at harvesting large pearls, especially in

7684-524: The airway and providing five breaths of mouth-to-mouth resuscitation . Cardiopulmonary resuscitation (CPR) is recommended for a person whose heart has stopped beating and has been underwater for less than an hour. A major contributor to drowning is the inability to swim. Other contributing factors include the state of the water itself, distance from a solid footing, physical impairment, or prior loss of consciousness. Anxiety brought on by fear of drowning or water itself can lead to exhaustion, thus increasing

7797-487: The airway is open through the trachea. There is also bronchospasm and mucous production in the bronchi associated with laryngospasm, and these may prevent water entry at terminal relaxation. The hypoxemia and acidosis caused by asphyxia in drowning affect various organs. There can be central nervous system damage, cardiac arrhythmia, pulmonary injury, reperfusion injury, and multiple-organ secondary injury with prolonged tissue hypoxia. A lack of oxygen or chemical changes in

7910-432: The airway, water in the stomach, cerebral edema and petrous or mastoid hemorrhage. Some evidence of immersion may be unrelated to the cause of death, and lacerations and abrasions may have occurred before or after immersion or death. Diatoms should normally never be present in human tissue unless water was aspirated. Their presence in tissues such as bone marrow suggests drowning; however, they are present in soil and

8023-500: The alveolar-capillary membrane. Still, there is no clinical difference between salt and freshwater drowning. Once someone has reached definitive care, supportive care strategies such as mechanical ventilation can help to reduce the complications of ALI/ARDS. Whether a person drowns in freshwater or salt water makes no difference in respiratory management or its outcome. People who drown in freshwater may experience worse hypoxemia early in their treatment; however, this initial difference

8136-405: The atmosphere, and samples may be contaminated. An absence of diatoms does not rule out drowning, as they are not always present in water. A match of diatom shells to those found in the water may provide supporting evidence of the place of death. Drowning in saltwater can leave different concentrations of sodium and chloride ions in the left and right chambers of the heart, but they will dissipate if

8249-471: The best conditions, a person was resuscitated after 65 minutes underwater. ‹The template How-to is being considered for merging .›   When a person is drowning or a swimmer becomes missing, a fast water rescue may become necessary, to take that person out of the water as soon as possible. Drowning is not necessarily violent or loud, with splashing and cries; it can be silent. Rescuers should avoid endangering themselves unnecessarily; whenever it

8362-473: The bi-annual AIDA Team World Championship, where the combined score of the team members makes up the team's total points, and Skandalopetra diving competitions held by CMAS, the only truly ‘team’ event in freediving for which teams are formed by two athletes: one acting as the diver ( βουτηχτής , voutichtis ) and the other acting as an assistant ( κολαουζέρης , kolaouzeris ). There are currently eleven recognized disciplines defined by AIDA and CMAS, and

8475-408: The blood after hyperventilation may then be insufficient to trigger the breathing reflex later in the dive. Following this, a blackout may occur before the diver feels an urgent need to breathe. This can occur at any depth and is common in distance breath-hold divers in swimming pools . Both deep and distance free divers often use hyperventilation to flush out carbon dioxide from the lungs to suppress

8588-407: The bloodstream and reduces the time until unconsciousness. The person can voluntarily hold their breath for some time, but the breathing reflex will increase until the person tries to breathe, even when submerged. The breathing reflex in the human body is weakly related to the amount of oxygen in the blood but strongly related to the amount of carbon dioxide (see Hypercapnia ). During an apnea,

8701-413: The bloodstream, and overall mental equilibrium. The most obvious hazard is lack of access to air for breathing – a necessity for human life. This can result in asphyxia from drowning if the diver does not reach the surface while still capable of holding their breath and resuming breathing. The risk depends on several factors, including the depth, duration and shape of the dive profile. Latent hypoxia

8814-651: The bottom. Traditionally it was a women's sport, but following the addition of a new mixed-pair event, FINA World Aquatics competitions are open to men since the 16th 2015 championships in Kazan , and the other international and national competitions allow male competitors in every event. However, men are currently still barred from competing in the Olympics. Both USA Synchro and Synchro Canada allow men to compete with women. Most European countries also allow men to compete, and France even allows male only podiums, according to

8927-423: The breathing reflex for longer. It is important not to mistake this for an attempt to increase the body's oxygen store. The body at rest is fully oxygenated by normal breathing and cannot take on any more. Breath-holding in water should always be supervised by a second person, as by hyperventilating, one increases the risk of shallow water blackout because insufficient carbon dioxide levels in the blood fail to trigger

9040-415: The breathing reflex. A continued lack of oxygen in the brain, hypoxia , will quickly render a person unconscious, usually around a blood partial pressure of oxygen of 25–30 mmHg. An unconscious person rescued with an airway still sealed from laryngospasm stands a good chance of a full recovery. Artificial respiration is also much more effective without water in the lungs. At this point, the person stands

9153-488: The capillaries to be carried to internal organs. The presence of these diatoms may be diagnostic of drowning. Of people who have survived drowning, almost one-third will experience complications such as acute lung injury (ALI) or acute respiratory distress syndrome (ARDS). ALI/ARDS can be triggered by pneumonia, sepsis, and water aspiration . These conditions are life-threatening disorders that can result in death if not treated promptly. During drowning, aspirated water enters

9266-781: The chance of survival should unconsciousness occur. Hypothermia (and cardiac arrest) presents a risk for survivors of immersion. This risk increases if the survivor—feeling well again—tries to get up and move, not realizing their core body temperature is still very low and will take a long time to recover. Most people who experience cold-water drowning do not develop hypothermia quickly enough to decrease cerebral metabolism before ischemia and irreversible hypoxia occur. The neuroprotective effects appear to require water temperatures below about 5 °C (41 °F). The World Health Organization in 2005 defined drowning as "the process of experiencing respiratory impairment from submersion/immersion in liquid." This definition does not imply death or even

9379-691: The chances of drowning. Approximately 90% of drownings take place in freshwater (rivers, lakes, and a relatively small number of swimming pools ); the remaining 10% take place in seawater . Drownings in other fluids are rare and often related to industrial accidents . In New Zealand's early colonial history, so many settlers died while trying to cross the rivers that drowning was called "the New Zealand death". People have drowned in as little as 30 mm (1.2 in) of water while lying face down. Death can occur due to complications following an initial drowning. Inhaled fluid can act as an irritant inside

9492-470: The circulation. It is also easy to gauge progress, as increasing distance can be measured. Before competition attempts, freedivers perform a preparation sequence, which usually consists of physical stretching, mental exercise and breath exercise. It may include a succession of variable length static apnea and special purging deep breaths. Results of the preparation sequence are slower metabolism, lower heart and breathing rates, lower levels of carbon dioxide in

9605-576: The cold winter months, when open-water diving lost its appeal. Underwater hockey is now played worldwide, governed by the Confédération Mondiale des Activités Subaquatiques (CMAS). The first Underwater Hockey World Championship was held in Canada in 1980, after a planned championship in 1979 was scuttled by international politics and apartheid . Underwater football is a two-team underwater sport that shares common elements with underwater hockey and underwater rugby . As with both of those games, it

9718-400: The deterioration of brain cells, causing first brain damage and eventually brain death after six minutes from which recovery is generally considered impossible. Hypothermia of the central nervous system may prolong this. In cold temperatures below 6 °C, the brain may be cooled sufficiently to allow for a survival time of more than an hour. The extent of central nervous system injury to

9831-464: The diver loses consciousness during the ascent. This is only reasonably practicable if the water clarity allows observation, and the buddy is capable of safely reaching the diver. Due to the nature of the sport, the risks of freediving can be reduced by strict adherence to safety measures as an integral part of the activity, but cannot be eliminated. Competition rules may require all participants to be adept in rescue and resuscitation. Nicholas Mevoli ,

9944-451: The diving reflex conflict with the body's cold shock response, which includes a gasp and uncontrollable hyperventilation leading to aspiration of water. While breath-holding triggers a slower heart rate , cold shock activates tachycardia , an increase in heart rate. It is thought that this conflict of these nervous system responses may account for the arrhythmias of cold water submersion. Heat transfers very well into water, and body heat

10057-540: The early stages of drowning, a person holds their breath to prevent water from entering their lungs. When this is no longer possible, a small amount of water entering the trachea causes a muscular spasm that seals the airway and prevents further passage of water. If the process is not interrupted, loss of consciousness due to hypoxia is followed by cardiac arrest. A conscious person will hold their breath (see Apnea ) and will try to access air, often resulting in panic , including rapid body movement. This uses up more oxygen in

10170-599: The exchange of oxygen and carbon dioxide in the body. Similar broad definitions of mechanical asphyxia have occurred in Saukko and Knight's 2004 book on asphyxia, and Dolinak and Matshes' 2005 book on forensic pathology. According to Shkrum and Ramsay, mechanical asphyxia encompasses smothering, choking, positional asphyxia, traumatic asphyxia, wedging, strangulation and drowning. Sauvageau and Boghossian propose in 2010 that mechanical asphyxia should be officially defined as caused by "restriction of respiratory movements, either by

10283-469: The following: The concept of water safety involves the procedures and policies that are directed to prevent people from drowning or from becoming injured in water. The time a person can safely stay underwater depends on many factors, including energy consumption, number of prior breaths, physical condition, and age. An average person can last between one and three minutes before falling unconscious and around ten minutes before dying. In an unusual case with

10396-451: The head. Another way to assist is to reach the victim with an object to grasp, and then pull both of them out of the water. Some examples include: ropes, oars, broad branches, poles, one's own arm, a hand, etc. This carries the risk of the rescuer being pulled into the water by the victim, so the rescuer must take a firm stand, lying down, as well as securing to some stable point. Any rescue with vehicles would have to avoid trampling or damaging

10509-561: The heavy sleeping adult may move on top of the infant, causing compression asphyxia. In fatal crowd disasters, compressive asphyxia from being crushed against the crowd causes all or nearly all deaths, rather than blunt trauma from trampling. This is what occurred at the Ibrox disaster in 1971, where 66 Rangers fans died; the 1979 The Who concert disaster where 11 died; the Luzhniki disaster in 1982, when 66 FC Spartak Moscow fans died;

10622-448: The lung tissues, causes a reduction in pulmonary surfactant , obstructs ventilation, and triggers a release of inflammatory mediators which results in hypoxia . Specifically, upon reaching the alveoli, hypotonic liquid found in freshwater dilutes pulmonary surfactant, destroying the substance. Comparatively, aspiration of hypertonic seawater draws liquid from the plasma into the alveoli and similarly causes damage to surfactant by disrupting

10735-399: The lungs may cause the heart to stop beating. This cardiac arrest stops the flow of blood and thus stops the transport of oxygen to the brain. Cardiac arrest used to be the traditional point of death, but at this point, there is still a chance of recovery. The brain cannot survive long without oxygen, and the continued lack of oxygen in the blood, combined with the cardiac arrest, will lead to

10848-454: The most difficult in forensic medicine. External examination and autopsy findings are often non-specific, and the available laboratory tests are often inconclusive or controversial. The purpose of an investigation is to distinguish whether the death was due to immersion or whether the body was immersed postmortem. The mechanism in acute drowning is hypoxemia and irreversible cerebral anoxia due to submersion in liquid. Drowning would be considered

10961-399: The necessity for medical treatment after removing the cause, nor that any fluid enters the lungs. The WHO classifies this as death , morbidity , and no morbidity. There was also consensus that the terms wet, dry, active, passive, silent, and secondary drowning should no longer be used. Experts differentiate between distress and drowning. Forensic diagnosis of drowning is considered one of

11074-407: The number of participants. In the past decade, more men are becoming involved in the sport and a global biannual competition called Men's Cup has been steadily growing. Swimmers perform two routines for the judges, one technical and one free, as well as age group routines and figures. Synchronized swimming is both an individual and team sport. Swimmers compete individually during figures, and then as

11187-454: The occasional use of reeds and leather breathing bladders. The divers faced the same problems as divers today, such as blacking out during a breath hold. Freediving was practiced in ancient cultures to gather food , harvest resources such as sponge and pearl , reclaim sunken valuables , and to help aid military campaigns . In Ancient Greece, both Plato and Homer mention the sponge as being used for bathing. The island of Kalymnos

11300-455: The opponent, and create openings for transitions , as the opponent is forced to react to the smothering. In some cases, when performing certain routines, smothering is combined with simultaneous compressive asphyxia. One example is overlay, in which an adult accidentally rolls over onto an infant during co-sleeping , an accident that often goes unnoticed and is mistakenly thought to be sudden infant death syndrome . Other accidents involving

11413-431: The organization's website. Alongside competitive disciplines, there are record disciplines — disciplines that are not held in competitions, that are just for setting world records. There is a third organization, Guinness , which in addition to AIDA and CMAS presides over record disciplines. Almost all types of competitive freediving are individual sports based on the best individual achievement. Exceptions to this rule are

11526-544: The oxygen in the body is used by the cells and excreted as carbon dioxide. Thus, the level of oxygen in the blood decreases, and the level of carbon dioxide increases. Increasing carbon dioxide levels lead to a stronger and stronger breathing reflex, up to the breath-hold breakpoint , at which the person can no longer voluntarily hold their breath. This typically occurs at an arterial partial pressure of carbon dioxide of 55 mm Hg but may differ significantly between people. When submerged into cold water, breath-holding time

11639-406: The passive collapse that is normal after death. Hemorrhagic bullae of emphysema may be found. These are related to the rupture of alveolar walls. These signs, while suggestive of drowning, are not conclusive. It is estimated that more than 85% of drownings could be prevented by supervision, training in water skills, technology, and public education. Measures that help to prevent drowning include

11752-411: The person survived for some time after the aspiration, or if CPR was attempted, and have been described in other causes of death. Most autopsy findings relate to asphyxia and are not specific to drowning. The signs of drowning are degraded by decomposition. Large amounts of froth will be present around the mouth and nostrils and in the upper and lower airways in freshly drowned bodies. The volume of froth

11865-547: The position of the body or by external chest compression", thus encompassing only positional asphyxia and traumatic asphyxia. If there are symptoms of mechanical asphyxia, it is necessary to call the Emergency Medical Services . In some countries, such as the US, there may also be self-acting groups of voluntary first responders who have been trained in first aid. In case of mechanical asphyxia, first aid can be provided on your own. In case of choking on

11978-412: The seabed. Divers would swim down to the wreck and choose the most valuable pieces to salvage. Divers were also used in warfare. Defenses against sea vessels were often created, such as underwater barricades , and hence divers were often used to scout out the seabed when ships were approaching an enemy harbor. If barricades were found, it was divers who were used to disassemble them, if possible. During

12091-517: The surface is very different from diving in open water. The time available to a freediver to solve problems underwater before hypoxia sets in is severely restricted in comparison with scuba. Freediving into confined cave systems such as Eagle's Nest Cave, Florida and Blue Springs State Park, Florida has resulted in several deaths. Cave freediving is commonly discouraged in basic freediver safety training. The human body has several oxygen-conserving adaptations that manifest under diving conditions as part of

12204-410: The surface. Trained freedivers are well aware of this and competitions must be held under strict supervision and with competent first-aiders on standby. However, this does not eliminate the risk of blackout. Freedivers are encouraged by certification and sporting organisations to dive only with a 'buddy' who accompanies them, observing from in the water at the surface, and ready to dive to the rescue if

12317-413: The vehicle, or following loss of consciousness to be followed by death while in a coma, having presented with anoxic brain damage. The asphyxia can be caused by facial compression, neck compression, or chest compression. This occurs mostly during restraint and handcuffing situations by law enforcement, including psychiatric incidents. The weight of the restraint(s) doing the compression may contribute to what

12430-400: The victim in another manner. Also, there are modern flying drones that can drop life jackets. Bystanders should immediately call for help. A lifeguard should be called, if present. If not, an emergency telephone number should be contacted as soon as possible, to get the help of professionals and paramedics . In some cases of drowning, victims have been rescued by professionals from a boat or

12543-542: The world for millennia. Early civilizations were familiar with the custom of spearing fish from rivers and streams using sharpened sticks. Today modern spearfishing makes use of elastic powered spearguns and slings, or compressed gas pneumatic powered spearguns, to strike the hunted fish. Specialised techniques and equipment have been developed for various types of aquatic environments and target fish. Spearfishing may be done using free-diving , snorkelling , or scuba diving techniques. Spearfishing while using scuba equipment

12656-477: Was a main centre of diving for sponges . By using weights ( skandalopetra ) of as much as 15 kilograms (33 lb) to speed the descent, breath-holding divers would descend to depths up to 30 metres (98 ft) to collect sponges. Harvesting of red coral was also done by divers. The Mediterranean had large amounts of maritime trade. As a result of shipwrecks , particularly in the fierce winter storms, divers were often hired to salvage whatever they could from

12769-479: Was first played at international level in 1993. It was recognised by the Confédération Mondiale des Activités Subaquatiques (CMAS) in 2008. Competitive spearfishing is defined by the world governing body CMAS as "the hunting and capture of fish underwater without the aid of artificial breathing devices, using gear that depends entirely on the physical strength of the competitor." They publish

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