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90-495: NACD is an acronym for: National Association for Cave Diving National Association of Corporate Directors National Association of Conservation Districts, a non-profit organization supported by the Natural Resources Conservation Service Topics referred to by the same term [REDACTED] This disambiguation page lists articles associated with

180-470: A breakdown of what factors contributed to the accident. Despite the unique circumstances of each individual accident, Exley found that at least one of a small number of major factors contributed to each one. This technique for breaking down accident reports and finding common causes among them is now called accident analysis , and is taught in introductory cave-diving courses. Exley outlined a number of these resulting cave-diving rules, but today these five are

270-581: A cave in 1934) can be directly associated to the exploration of the Dent de Crolles cave system. In 1941, American cavers organized themselves into the National Speleological Society (NSS) to advance the exploration, conservation, study and understanding of caves in the United States. American caver Bill Cuddington , known as "Vertical Bill", further developed the single-rope technique (SRT) in

360-403: A combination of these conditions. Losing the guide line in a cave is a potentially life-threatening emergency. While following recommended best practice makes it highly unlikely that a diver will lose the line, it can and does happen, and there are procedures which will usually work to find it again. Any reliable information on where the diver is likely to be relative to the last known position of

450-810: A community discussion and analysis of accidents through a "Cave Diver Safety Meeting" held annually. Equipment used by cave divers ranges from fairly standard recreational scuba configurations, to more complex arrangements which allow more freedom of movement in confined spaces, extended range in terms of depth and time, allowing greater distances to be covered in acceptable safety, and equipment which helps with navigation, in what are usually dark, and often silty and convoluted spaces. Scuba configurations which are more often found in cave-diving than in open water diving include independent or manifolded twin cylinder rigs, side-mount harnesses, sling cylinders , rebreathers and backplate and wing harnesses. Bill Stone designed and used epoxy composite tanks for exploration of

540-442: A dissolution of existing features. Pollution is also of concern. Since water that flows through a cave eventually comes out in streams and rivers, any pollution may ultimately end up in someone's drinking water, and can even seriously affect the surface environment, as well. Even minor pollution such as dropping organic material can have a dramatic effect on the cave biota. Cave-dwelling species are also very fragile, and often,

630-415: A dive, and the monitoring and switching of breathing gases during a dive, 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 and oxygen toxicity risk. The rule of thirds for gas management

720-503: A flexible metal ladder . In addition to the equipment already described, cavers frequently carry packs containing first-aid kits, emergency equipment, and food. Containers for securely transporting urine are also commonly carried. On longer trips, containers for securely transporting feces out of the cave are carried. During very long trips, it may be necessary to camp in the cave – some cavers have stayed underground for many days, or in particularly extreme cases, for weeks at

810-413: A guiding service (e.g. Lava River Cave , the oceanic islands of Tenerife , Iceland and Hawaii ). Caving has also been described as an "individualist's team sport" by some, as cavers can often make a trip without direct physical assistance from others but will generally go in a group for companionship or to provide emergency help if needed. Some however consider the assistance cavers give each other as

900-446: A larger volume of gas than he alone requires. A different option for penetration dives is the Half + 15 bar (half + 200 psi) method, in which the contingency gas for the stage is carried in the primary cylinders. Some divers consider this method to be the most conservative when multi-staging. If all goes to plan when using this method, the divers surface with stages nearly empty, but with all

990-546: A light and not realize how far away from the entrance (and daylight) one has swum; this rule is based on the theory that, without a light, divers will not venture beyond daylight. In the early phases of cave-diving the analysis shows that 90% of accidents were not trained cave divers; from the 2000s on the trend has reversed to 80% of accidents involving trained cave divers. Modern cave divers' capability and available technology allows divers to venture well beyond traditional training limits and into actual exploration. The result

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1080-441: A method that would be ideal for one situation might not work at all for another. If the line is found, but not the other divers, the diver can tie off their search reel to the guide line as an indicator to other members of the team that they were lost but have found the guide line, and indicate the direction that they intend to proceed along the guideline with a personal directional marker so that others who see it while searching for

1170-525: A particular species found in a cave may live within that cave alone, and be found nowhere else in the world, such as Alabama cave shrimp . Cave-dwelling species are accustomed to a near-constant climate of temperature and humidity, and any disturbance can be disruptive to the species' life cycles. Though cave wildlife may not always be immediately visible, it is typically nonetheless present in most caves. Bats are one such fragile species of cave-dwelling animal. Bats which hibernate are most vulnerable during

1260-534: A pristine floor of sand or silt which may be thousands of years old, dating from the last time water flowed through the cave. Such deposits may easily be spoiled forever by a single misplaced step. Active formations such as flowstone can be similarly marred with a muddy footprint or handprint, and ancient human artifacts, such as fiber products, may even crumble to dust under all but the most gentle touch. In 1988, concerned that cave resources were becoming increasingly damaged through unregulated use, Congress enacted

1350-442: A search, which will depend on the stage of the dive when the diver is noticed to be missing. When searching in darkness, the searchers should periodically turn off their lights as this will allow them to see the lost diver's light more easily. Gas planning is the aspect of dive planning which deals with the calculation or estimation of the amounts and mixtures of gases to be used for a planned dive profile . It usually assumes that

1440-537: A self-taught approach is discouraged. The following training courses are offered by the listed organisations: Diver In France, courses organized by the national cave diving commission of the FFESSM , are offered to holders of level 2 certification or higher. The French Cave Diving School of the FFS also offers courses open to any autonomous diver . A significant aspect of cave diving by competent and enthusiastic cave divers

1530-467: A single dive. While a less-intensive kind of diving called cavern diving does not take divers beyond the reach of natural light (and typically no deeper than 30 metres (100 feet)), and penetration not further than 60 m (200 ft), true cave-diving can involve penetrations of many thousands of feet, well beyond the reach of sunlight. The level of darkness experienced creates an environment impossible to see in without an artificial source of light even if

1620-584: A technical diving challenge. Underwater caves have a wide range of physical features, and can contain fauna not found elsewhere. Several organisations dedicated to cave diving safety and exploration exist, and several agencies provide specialised training in the skills and procedures considered necessary for acceptable safety. Two types of overhead diving environment are defined in recreational cave diving: The underwater cave environment includes those parts of caves which may be explored underwater. Recreational cave diving can be defined as diving underground beyond

1710-424: A time. This is particularly the case when exploring or mapping extensive cave systems, where it would be impractical to retrace the route back to the surface regularly. Such long trips necessitate the cavers carrying provisions, sleeping, and cooking equipment. Caves can be dangerous places; hypothermia, falling , flooding , falling rocks and physical exhaustion are the main risks. Rescuing people from underground

1800-495: A typical team sport activity. The term potholing refers to the act of exploring potholes , a word originating in the north of England for predominantly vertical caves . Clay Perry , an American caver of the 1940s, wrote about a group of men and boys who explored and studied caves throughout New England . This group referred to themselves as spelunkers , a term derived from the Latin spēlunca ("cave, cavern, den"). This

1890-546: Is underwater diving in water-filled caves . It may be done as an extreme sport, a way of exploring flooded caves for scientific investigation, or for the search for and recovery of divers or, as in the 2018 Thai cave rescue , other cave users. The equipment used varies depending on the circumstances, and ranges from breath hold to surface supplied , but almost all cave-diving is done using scuba equipment , often in specialised configurations with redundancies such as sidemount or backmounted twinset. Recreational cave-diving

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1980-418: Is a rule of thumb used by divers to plan dives so they have enough breathing gas remaining in their diving cylinder at the end of the dive to be able to complete the dive safely. This rule mostly applies to diving in overhead environments, such as caves and wrecks, where a direct ascent to the surface is impossible and the divers must return the way they came. For divers following the rule, one third of

2070-399: Is a distinct, and more hazardous, sub-speciality undertaken by a small minority of technically proficient cavers. In an area of overlap between recreational pursuit and scientific study, the most devoted and serious-minded cavers become accomplished at the surveying and mapping of caves and the formal publication of their efforts. These are usually published freely and publicly, especially in

2160-548: Is an increase of cave-diving accidents, in 2011 the yearly average of 2.5 fatalities a year tripled. In 2012 fatalities reached the highest annual rate to that date at over 20. As response to the increase in fatalities during the years 2010 onwards, the International Diving Research and Exploration Organization (IDREO) was created in order to "bring awareness of the current safety situation of Cave Diving" by listing current worldwide accidents by year and promoting

2250-550: Is coming up out of the Earth and flowing out across the land's surface. Siphons have in-flowing currents where, for example, an above-ground river is going underground. Some caves are complex and have some tunnels with out-flowing currents, and other tunnels with in-flowing currents. Inflowing currents can cause serious problems for the diver, as they make the exit more difficult, and the diver is carried to spaces that are unfamiliar and may be dangerous, while outflowing currents generally make

2340-400: Is difficult and time-consuming, and requires special skills, training, and equipment. Full-scale cave rescues often involve the efforts of dozens of rescue workers (often other long-time cavers who have participated in specialized courses, as normal rescue staff are not sufficiently experienced in cave environments), who may themselves be put in jeopardy in effecting the rescue. This said, caving

2430-407: Is ensured by the use of a continuous guideline between the dive team and a point outside of the flooded part of the cave, and diligent planning and monitoring of gas supplies. Two basic types of guideline are used: permanent lines, and temporary lines. Permanent lines may include a main line starting near the entrance/exit, and side lines or branch lines, and are marked to indicate the direction along

2520-409: Is exploration, survey and mapping. Data collected is often shared and may be stored on databases to help optimise the effectiveness of such surveys, and make the information generally available. Underwater cave mapping is complicated by both a lack of access to the surface for GPS positions, darkness, with short line-of-sight, and limited visibility, which complicate optical measurement. Altitude/depth

2610-437: Is generally considered to be a type of technical diving due to the lack of a free surface during large parts of the dive, and often involves planned decompression stops. A distinction is made by recreational diver training agencies between cave-diving and cavern-diving, where cavern diving is deemed to be diving in those parts of a cave where the exit to open water can be seen by natural light. An arbitrary distance limit to

2700-413: Is not necessarily a high-risk sport (especially if it does not involve difficult climbs or diving). As in all physical sports, knowing one's limitations is key. Caving in warmer climates carries the risk of contracting histoplasmosis , a fungal infection that is contracted from bird or bat droppings. It can cause pneumonia and can disseminate in the body to cause continued infections. In many parts of

2790-488: Is often undertaken for the enjoyment of the outdoor activity or for physical exercise, as well as original exploration, similar to mountaineering or diving . Physical or biological science is also an important goal for some cavers, while others are engaged in cave photography. Virgin cave systems comprise some of the last unexplored regions on Earth and much effort is put into trying to locate, enter and survey them. In well-explored regions (such as most developed nations),

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2880-568: Is regarded as the first use of the word in the Americas . Throughout the 1950s, spelunking was the general term used for exploring caves in US English . It was used freely, without any positive or negative connotations, although only rarely outside the US. In the 1960s, the terms spelunking and spelunker began to be considered déclassé among experienced enthusiasts. In 1985, Steve Knutson – editor of

2970-496: Is relatively simple as accurate depth measurement is available to divers in the form of decompression computers, which log a depth/time record of reasonable accuracy and are available for instantaneous readout at any point, and depth can be referenced to the altitude at the surface. Vertical dimensions can be directly measured or calculated as differences in depth. Surface coordinates can be collected via GPS and remote sensing, with varying degrees of precision and accuracy depending on

3060-472: Is statistically much safer than recreational diving due to the much larger barriers imposed by experience, training, and equipment cost, but there is no definitive statistical evidence for this claim. There is no reliable worldwide database listing all cave-diving fatalities. Such fractional statistics as are available, however, suggest that few divers have died while following accepted protocols and while using equipment configurations recognized as acceptable by

3150-438: Is to ensure that for all reasonably foreseeable contingencies, the divers of a team have sufficient breathing gas to safely return to a place where more breathing gas is available. In almost all cases this will be the surface. Gas planning includes the following aspects: The primary breathing apparatus may be open circuit scuba or rebreather, and bailout may also be open circuit or rebreather. Emergency gas may be shared among

3240-434: Is used, to provide some abrasion protection while remaining as cool as possible. Wetsuits may be worn if the cave is particularly wet or involves stream passages. On the feet boots are worn – hiking-style boots in drier caves, or rubber boots (such as wellies ) often with neoprene socks ("wetsocks") in wetter caves. Knee -pads (and sometimes elbow -pads) are popular for protecting joints during crawls. Depending on

3330-507: The Dent de Crolles cave system near Grenoble , which became the deepest explored system in the world (-658m) at that time. The lack of available equipment during the war forced Pierre Chevalier and the rest of the team to develop their own equipment, leading to technical innovation. The scaling-pole (1940), nylon ropes (1942), use of explosives in caves (1947) and mechanical rope-ascenders (Henri Brenot's "monkeys", first used by Chevalier and Brenot in

3420-587: The Federal Cave Resources Protection Act , giving land management agencies in the United States expanded authority to manage cave conservation on public land. Cavers in many countries have created organizations for the administration and oversight of caving activities within their nations. The oldest of these is the French Federation of Speleology (originally Société de spéléologie) founded by Édouard-Alfred Martel in 1895, which produced

3510-426: The National Speleological Society (NSS) publication American Caving Accidents  – made the following distinction: …Note that (in this case) the term 'spelunker' denotes someone untrained and unknowledgeable in current exploration techniques, and 'caver' is for those who are. This sentiment is exemplified by bumper stickers and T-shirts displayed by some cavers: "Cavers rescue spelunkers". Nevertheless, outside

3600-432: The rappel rack and the evolution of mechanical ascension systems extended the practice and safety of vertical exploration to a wider range of cavers. Hard hats are worn to protect the head from bumps and falling rocks. The caver's primary light source is usually mounted on the helmet in order to keep the hands free. Electric LED lights are most common. Many cavers carry two or more sources of light – one as primary and

3690-801: The 1890s, Balch was introduced to the caves of the Mendip Hills . One of the oldest established caving clubs, Yorkshire Ramblers' Club , was founded in 1892. Caving as a specialized pursuit was pioneered by Édouard-Alfred Martel (1859–1938), who first achieved the descent and exploration of the Gouffre de Padirac , in France, as early as 1889 and the first complete descent of a 110-metre wet vertical shaft at Gaping Gill in 1895. He developed his own techniques based on ropes and metallic ladders. Martel visited Kentucky and notably Mammoth Cave National Park in October 1912. In

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3780-713: The 1920s famous US caver Floyd Collins made important explorations in the area and in the 1930s, as caving became increasingly popular, small exploration teams both in the Alps and in the karstic high plateaus of southwest France ( Causses and Pyrenees ) transformed cave exploration into both a scientific and recreational activity. Robert de Joly , Guy de Lavaur and Norbert Casteret were prominent figures of that time, surveying mostly caves in Southwest France. During World War II , an alpine team composed of Pierre Chevalier , Fernand Petzl , Charles Petit-Didier and others explored

3870-507: The San Agustín and Sistema Huautla caves in Mexico to decrease the weight for dry sections and vertical passages. Stage cylinders are cylinders which are used to provide gas for a portion of the penetration. They may be deposited on the bottom at the guideline on preparation dives, to be picked up for use during the main dive, or may be carried by the divers and dropped off at the line during

3960-461: The UK and other European countries, although in the US they are generally more private. Although caving is sometimes categorized as an " extreme sport ," cavers do not commonly use this terminology and typically dislike the term being used in reference to caving, as it implies a disregard for safety. Many caving skills overlap with those involved in canyoning and mine and urban exploration . Caving

4050-482: The United States are more closely associated with recreational scuba diving . Compared to caving and scuba diving, there are relatively few practitioners of cave-diving. This is due in part to the specialized equipment and skill sets required, and in part because of the high potential risks due to the specific environment. Despite these risks, water-filled caves attract scuba divers, cavers , and speleologists due to their often unexplored nature, and present divers with

4140-404: The buddy may know where the line is, and can be asked, and if the diver is separated from their buddy, the buddy may be at the line, and the buddy's light may be visible. Stabilising the position is generally done by finding the nearest feasible tie-off point and securely tying off a search line. The direction of the guide line when last seen should be known, and therefore the direction the diver

4230-703: The cave along the dive route will constrain decompression depths, and gas mixtures and decompression schedules can be tailored to take this into account. Most open-water diving skills apply to cave-diving, and there are additional skills specific to the environment, and to the chosen equipment configuration. The essential cave-diving procedure is navigation using a guide line. This includes laying and marking line, following line and interpreting line markers, avoiding entanglement, recovering from entanglement, maintaining and repairing line, finding lost line, jumping gaps, and recovering line, any of which may need to be done in zero visibility, total darkness, tight confined spaces or

4320-574: The cave line, measurements of height, width, depth, and slope at intervals along the line, generally using a permanent guide line as a reference baseline , and take photographic records of features and objects of interest. Data are collected on wet-notes and by digital photography. Hand-held sonar may be used for distance measurement where available. Where the depth or other constraints prevent divers from exploring in person, tethered and untethered remotely operated underwater vehicles (ROUVs) have been used effectively, using sonar technology to scan and map

4410-467: The cave-diving community. In the very rare cases of exceptions to this rule there have typically been unusual circumstances. Most cave divers recognize five general rules or contributing factors for safe cave-diving, which were popularized, adapted and became generally accepted from Sheck Exley 's 1979 publication Basic Cave Diving: A Blueprint for Survival . In this book, Exley included accounts of actual cave-diving accidents, and followed each one with

4500-462: The caving community, "spelunking" and "spelunkers" predominately remain neutral terms referring to the practice and practitioners, without any respect to skill level. In the mid-nineteenth century, John Birkbeck explored potholes in England, notably Gaping Gill in 1842 and Alum Pot in 1847–8, returning there in the 1870s. In the mid-1880s, Herbert E. Balch began exploring Wookey Hole Caves and in

4590-423: The contingency gas still in their primary cylinders. With a single stage drop, this means the primary cylinders will still be about half-full. Cave-diving training includes equipment selection and configuration, guideline protocols and techniques, gas management protocols, communication techniques, propulsion techniques, emergency management protocols, and psychological education. Cave diver training also stresses

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4680-558: The depth, or swept away by strong flow. Getting lost means separation from the continuous guide line to the exit, and not knowing the direction to the exit. Some cave divers are taught to remember the five key components with the mnemonic : " T he G ood D ivers A lways L ive " (training, guide, depth, air, light). In recent years new contributing factors were considered after reviewing accidents involving solo diving, diving with incapable dive partners, video or photography in caves, complex cave dives and cave-diving in large groups. With

4770-474: The dive profile, including decompression, is known, but the process may be iterative, involving changes to the dive profile as a consequence of the gas requirement calculation, or changes to the gas mixtures chosen. Use of calculated reserves based on planned dive profile and estimated gas consumption rates rather than an arbitrary pressure based on a fraction of the initial gas supply is sometimes referred to as rock bottom gas management. The purpose of gas planning

4860-405: The emphasis on navigation, gas management, operating in confined spaces, and that the diver is physically constrained from direct ascent to the surface during much of the dive. As most cave-diving is done in an environment where there is no free surface with breathable air allowing an above-water exit, it is critically important to be able to find the way out before the breathing gas runs out. This

4950-444: The environment of the cave being explored, and the local culture. In cold caves, the caver may wear a warm base layer that retains its insulating properties when wet, such as a fleece ("furry") suit or polypropylene underwear, and an oversuit of hard-wearing (e.g., cordura ) or waterproof (e.g., PVC ) material. Lighter clothing may be worn in warm caves, particularly if the cave is dry, and in tropical caves thin polypropylene clothing

5040-464: The establishment of technical diving, the use of mixed gases—such as trimix for bottom gas, and nitrox and oxygen for decompression—reduces the margin for error. Accident analysis suggests that breathing the wrong gas for the depth or not analyzing the breathing gas properly has also led to cave-diving accidents. Cave-diving requires a variety of specialized procedures, and divers who do not correctly apply these procedures may significantly increase

5130-418: The estimated position of the line and slowly paying out search line, the diver will search visually, and in low visibility or darkness, also by feel, making arm sweeps across the expected direction of the line, while defending the head from impact with the other arm. The distance swum towards the estimated position of the lost line can be measured by the spacing and number of knots paid out on the search line. If

5220-440: The exit quicker and the diver is carried through places they have been before and can be prepared for difficult areas. Cave-diving has been perceived as one of the more deadly sports in the world. This perception may be exaggerated because the majority of divers who have died in caves have either not undergone specialized training or have had inadequate equipment for the environment. Some cave divers have suggested that cave-diving

5310-472: The first periodical journal in speleology, Spelunca . The first University-based speleological institute in the world was founded in 1920 in Cluj-Napoca , Romania, by Emil Racovita , a Romanian biologist, zoologist, speleologist and explorer of Antarctica. The British Speleological Association was established in 1935 and the National Speleological Society in the US was founded in 1941 (originally formed as

5400-411: The gas supply is planned for the outward journey, one third is for the return journey and one third is a safety reserve. However, when diving with a buddy with a higher breathing rate or a different volume of gas, it may be necessary to set one third of the buddy's gas supply as the remaining 'third'. This means that the turn point to exit is earlier, or that the diver with the lower breathing rate carries

5490-437: The guide line indicating the direction to the exit before starting a search. The search line can be tied to the directional marker to prevent it from sliding along the line during the search. The direction for the search would depend on the layout of that part of the cave, and where the missing diver should have been in the group. The search party must consider their own safety first, regarding how much gas they can afford to use in

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5580-412: The importance of risk management and cave conservation ethics. Most training systems offer progressive stages of education and certification. Various diver training and certification organizations offer training for cave divers, often based on the three cave zones defined by CMAS. Some organizations offer cavern diving training for recreational divers, (Zone 1). Cave diving involves significant risks, so

5670-621: The late 1950s. In 1958, two Swiss alpinists, Juesi and Marti teamed together, creating the first rope ascender known as the Jumar . In 1968 Bruno Dressler asked Fernand Petzl, who worked as a metals machinist, to build a rope-ascending tool, today known as the Petzl Croll , that he had developed by adapting the Jumar to vertical caving. Pursuing these developments, Petzl started in the 1970s a caving equipment manufacturing company named Petzl . The development of

5760-401: The line may be critical, and the procedure of choice will depend on what is reliably known. In all situations, the diver will attempt to stabilise the situation and avoid getting further lost, and make a thorough visual check in all directions from where they are at the time, taking into account the possibility of the line being in a line trap. If the diver has not also separated from their buddy,

5850-430: The line to the nearest exit. Temporary lines include exploration lines and jump lines. Decompression procedures may take into account that the cave diver usually follows a very rigidly constrained and precisely defined route, both into and out of the cave, and can reasonably expect to find any equipment such as drop cylinders temporarily stored along the guideline while making the exit. In some caves, changes of depth of

5940-413: The lost diver will know whether the diver chose the right direction to exit the cave. This is generally the converse situation to the lost guide line, in that the diver loses contact with their buddy or team but remains in contact with the guide line, so is not themselves lost. Their first priority is to not get lost or disorientated, and in furtherance of this aim would attach a directional line marker to

6030-555: The most accessible caves have already been explored, and gaining access to new caves often requires cave digging or cave diving. Caving, in certain areas, has also been utilized as a form of eco and adventure tourism, for example in New Zealand . Tour companies have established an industry leading and guiding tours into and through caves. Depending on the type of cave and the type of tour, the experience could be adventure-based or ecological-based. There are tours led through lava tubes by

6120-438: The most recognized: Most cave-diving fatalities are due to running out of gas before reaching the exit. This is often the direct consequence of getting lost, whether the guide line is found again or not, and whether the visibility deteriorates, lights fail, or someone panics. On rare occasions equipment failure is unrecoverable, or a diver becomes inextricably trapped, seriously injured, incapacitated by using an unsuitable gas for

6210-522: The naturally illuminated part of underwater caves, where the risk of getting lost is small, as the exit can be seen, and the equipment needed is reduced due to the limited distance to surface air. It is defined as a recreational diving activity as opposed to a technical diving activity on the grounds of low risk and basic equipment requirements. The procedures of cave-diving have much in common with procedures used for other types of penetration diving . They differ from open-water diving procedures mainly in

6300-610: The nature of the cave, gloves are sometimes worn to protect the hands against abrasion or cold. In pristine areas and for restoration, clean oversuits and powder-free, non-latex surgical gloves are used to protect the cave itself from contaminants. Ropes are used for descending or ascending pitches (single rope technique or SRT) or for protection. Knots commonly used in caving are the figure-of-eight - (or figure-of-nine -) loop, bowline , alpine butterfly , and Italian hitch . Ropes are usually rigged using bolts , slings , and carabiners . In some cases cavers may choose to bring and use

6390-409: The nearest point on the main line. Line used for this purpose is known as cave line . Gap spools with a relatively short line are commonly used to make the jump . Caving The challenges involved in caving vary according to the cave being visited; in addition to the total absence of light beyond the entrance, negotiating pitches , squeezes, and water hazards can be difficult. Cave diving

6480-445: The open water surface may also be specified. Equipment , procedures , and the requisite skills have been developed to reduce the risk of becoming lost in a flooded cave, and consequently drowning when the breathing gas supply runs out. The equipment aspect largely involves the provision of an adequate breathing gas supply to cover reasonably foreseeable contingencies, redundant dive lights and other safety critical equipment, and

6570-430: The others as backup in case the first fails. More often than not, a second light will be mounted to the helmet for quick transition if the primary fails. Carbide lamp systems are an older form of illumination, inspired by miner's equipment, and are still used by some cavers, particularly on remote expeditions where electric charging facilities are not available. The type of clothes worn underground varies according to

6660-399: The penetration to be retrieved on the way out. One of the high risk hazards of cave-diving is getting lost in the cave. The use of guide lines is the standard mitigation for this risk. Guide lines may be permanent or laid and recovered during the dive, using cave reels to deploy and recover the line. Permanent branch lines may be laid with a gap between the start of the branch line and

6750-410: The reach of natural daylight, as a way of distinguishing between cave and cavern diving. In this context, while artificially formed underground spaces such as mines are not generally called caves by divers, the activity of diving in them is classed as cave diving for training and certification purposes by diver training agencies Cavern diving is an arbitrarily defined, limited scope activity of diving in

6840-458: The risk to the members of their team. The cave-diving community works hard to educate the public on the risks they assume when they enter water-filled caves. Warning signs with the likenesses of the Grim Reaper have been placed just inside the openings of many popular caves in the US and Mexico, and others have been placed in nearby parking lots and local dive shops. Many cave-diving sites around

6930-414: The search fails, the diver will return to the tie off and try again in the next best guess for the direction the line may be. The diver may also choose to try a different search method. The best search method for any given situation will depend on the water conditions, the layout of the section of cave, the way the line was laid, the situational knowledge and skills of the diver, and the equipment available –

7020-469: The slightest touch and some by impacts as slight as a breath. Research suggests that increased carbon dioxide levels can lead to "a higher equilibrium concentration of calcium within the drip waters feeding the speleothems, and hence causes dissolution of existing features." In 2008, researchers found evidence that respiration from cave visitors may generate elevated carbon dioxide concentrations in caves, leading to increased temperatures of up to 3 °C and

7110-457: The surface due to the cave's ceilings, and so must swim the entire way back out. The underwater navigation through the cave system may be difficult and exit routes may be at a considerable distance, requiring the diver to have sufficient breathing gas to make the journey. The dive may also be deep, resulting in potential deep diving risks. Visibility can vary from nearly unlimited to low, or non-existent, and can go from very good to very bad in

7200-417: The surroundings, and video to record the appearance. Features, artifacts, remains, and other objects of interest are recorded in situ as effectively as possible, generally by photography. Cave-diving is one of the most challenging and potentially dangerous kinds of diving and presents many hazards . Cave-diving is a form of penetration diving , meaning that in an emergency a diver cannot swim vertically to

7290-489: The team members, or each diver may carry their own, but in all cases each diver must be able to bail out onto a gas supply of their own for long enough to get to the next planned source of emergency gas. If for any reason this situation no longer applies, there is a single point of critical failure, and the risk becomes unacceptable, so the dive should be turned. Gas management also includes the blending, filling, analysing, marking, storage, and transportation of gas cylinders for

7380-476: The title NACD . If an internal link led you here, you may wish to change the link to point directly to the intended article. Retrieved from " https://en.wikipedia.org/w/index.php?title=NACD&oldid=1180269520 " Category : Disambiguation pages Hidden categories: Short description is different from Wikidata All article disambiguation pages All disambiguation pages National Association for Cave Diving Cave-diving

7470-577: The type of entrance. In some caves the water surface is in view of GPS satellites, in others it is a considerable distance along a complex route from the nearest open air. Three dimensional models of varying accuracy and detail can be created by processing measurements collected by whatever methods were available. These can be used in virtual reality models. The usual methods for survey and mapping of underwater caves are dead reckoning and direct measurements of distance, compass direction and depth, by diving teams of two or three scuba divers, who record azimuth of

7560-475: The use of a continuous guideline leading the divers back out of the overhead environment . The skills and procedures include effective management of the equipment, and procedures to recover from foreseeable contingencies and emergencies, both by individual divers, and by the teams that dive together. In the United Kingdom, cave-diving developed from the locally more common activity of caving . Its origins in

7650-659: The warmer months when they are most sensitive and vulnerable. Due to an affliction affecting bats in the northeastern US known as white nose syndrome (WNS), the US Fish & Wildlife Service has called for a moratorium effective March 26, 2009, on caving activity in states known to have hibernacula (MD, NY, VT, NH, MA, CT, NJ, PA, VA, and WV) affected by WNS, as well as adjoining states. Some cave passages may be marked with flagging tape or other indicators to show biologically, aesthetically, or archaeologically sensitive areas. Marked paths may show ways around notably fragile areas such as

7740-445: The water is clear. Caves often contain sand, mud, clay, silt, or other sediment that can further reduce underwater visibility in seconds when stirred up. Consequently, visibility is often worse during exit, and divers rely on the guideline for finding the way out. The water in caves can have strong flow . Most caves flooded to the surface at the cave mouth are either springs or siphons . Springs have out-flowing currents, where water

7830-408: The winter season, when no food supply exists on the surface to replenish the bat's store of energy should it be awakened from hibernation. Bats which migrate are most sensitive during the summer months when they are raising their young. For these reasons, visiting caves inhabited by hibernating bats is discouraged during cold months; and visiting caves inhabited by migratory bats is discouraged during

7920-440: The world include open-water basins, which are popular open-water diving sites. The management of these sites try to minimize the risk of untrained divers being tempted to venture inside the cave systems. With the support of the cave-diving community, many of these sites enforce a "no-lights rule" for divers who lack cave training—they may not carry any lights into the water with them. It is easy to venture into an underwater cave with

8010-427: The world, leptospirosis ("a type of bacterial infection spread by animals" including rats ) is a distinct threat, owing to the presence of rat urine in rainwater or precipitation that enters the caves water system. Complications are uncommon, but can be serious. Safety risks while caving can be minimized by using a number of techniques: Many cave environments are very fragile. Many speleothems can be damaged by even

8100-520: Was swimming in before losing the line. If the diver was neutrally buoyant while following the line, the approximate depth can be reconstructed by finding the depth of neutral buoyancy again, without adjusting inflation of BCD or dry suit. Unless the line was lost by the diver not noticing a change of direction, it is likely to be at much the same depth, in much the same direction, and at a similar lateral and vertical distance as when last seen, making it logical to try that direction first. While swimming towards

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