Freediving

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Freediver with monofin, ascending

Freediving, free-diving, or free diving is a form of underwater diving that relies on a diver's ability to hold his or her breath until resurfacing rather than on the use of a breathing apparatus such as scuba gear. Recognised examples of freediving activities include traditional fishing techniques, competitive and non-competitive freediving, competitive and non-competitive spearfishing and freediving photography. Less recognised examples include, but are not limited to, synchronized swimming, underwater rugby, underwater hockey, underwater hunting other than spearfishing, underwater target shooting and snorkeling. The term 'freediving' is often associated with competitive breath-hold diving or competitive apnea. However, while some regard freediving as a specific group of underwater activities for others it as merely a synonym for breath-hold diving. The activity that attracts the most public attention is the extreme sport of competitive apnea in which competitors attempt to attain great depths, times, or distances on a single breath.

History[edit]

See also: Sponge diving
Natural sponges have been harvested by freedivers near the Greek island of Kalymnos since at least the time of Plato.

Frediving was practised in ancient cultures to gather food, harvest resources like sponge and pearl, reclaim sunken valuables, and to help aid military campaigns. In ancient times free diving without the aid of mechanical devices was the only possibility, with the exception of the occasional use of reeds and leather breathing bladders.[1] The divers faced the same problems as divers today, such as decompression sickness and blacking out during a breath hold. Because of these dangers, diving in antiquity could be quite deadly.

Freediving for commercial, rather than recreational purposes may have begun in Ancient Greece, since both Plato and Homer mention the sponge as being used for bathing. The island of Kalymnos 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) for as much as 5 minutes to collect sponges.[2] Sponges weren't the only valuable harvest to be found on the sea floor; the harvesting of red coral was also quite popular. A variety of valuable shells or fish could be harvested in this way creating a demand for divers to harvest the treasures of the sea, which could also include the sunken riches of other seafarers. The Ama Divers from Japan began to collect pearls about 2,000 years ago.[3][4]

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 the seabed.[5] Divers would swim down to the wreck and choose the most valuable pieces to salvage. These salvage divers faced many dangers on the job, and as a result, laws, such as the ''Lex Rhodia'', were enacted that awarded a large percentage of the salvage to the divers; in wrecks deeper than 50 feet, divers received one third of the salvage and in wrecks deeper than 90 feet they received half.

Divers were also used in warfare. Defenses against sea vessels were often created, such as underwater barricades aimed at sinking enemy ships. As the barricades were hidden under the water, divers were often used to scout out the sea bed when ships were approaching an enemy harbor. Once these barricades were found it was divers who were used to disassemble them, if possible.[6] During 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 by the blockade.[7] On top of all that these ancient frogmen were used as saboteurs, drilling holes in enemy hulls, cutting ships rigging and mooring.[citation needed]

Competition[edit]

Competitive freediving is currently governed by two world associations: AIDA International (International Association for Development of Apnea)[8] and CMAS (World Underwater Federation). Most types of competitive freediving have in common that it is an individual sport based on the best individual achievement. An exception to this rule is the bi-annual World Championship for Teams, held by AIDA, where the combined score of the team members makes up the team's total points. There are currently nine disciplines used by official governing bodies and a dozen disciplines that are only practiced locally. In this article, the recognized disciplines of AIDA and CMAS will be described. All disciplines can be done by both men and women and, while done outdoors, no differences in the environment between records are recognized any longer. 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 done solely as record attempts.

The following official disciplines are recognized by AIDA, CMAS, or both.

Pool disciplines[edit]

Monofin freediver holding his breath and swimming underwater

Depth disciplines[edit]

For all AIDA disciplines, the depth the athlete will attempt is announced before the dive. This is accepted practice for both competitions and record attempts.

Each organization has its own rules on recognizing an attempt. These can be found on the website from the respective organizations.

Herbert Nitsch, World Record Holder Freediver

AIDA recognized world records[edit]

As of 19 July 2014, the AIDA recognized world records are:[9]

DisciplineGenderDepth [m]Distance [m]TimeNameDatePlace
Constant weight apnea (CWT)Men128--Alexey Molchanov2013-09-19Kalamata, Greece
Constant weight apnea (CWT)Women101--Natalia Molchanova2011-09-22Kalamata, Greece
Constant weight apnea without fins (CNF)Men101--William Trubridge2010-12-16Dean's Blue Hole, Long Island Bahamas
Constant weight apnea without fins (CNF)Women70--Natalia Molchanova2014-05-15Dahab, Egypt
Free immersion apnea (FIM)Men121--William Trubridge2011-04-10Dean's Blue Hole, Long Island Bahamas
Free immersion apnea (FIM)Women91--Natalia Molchanova2013-09-21Kalamata, Greece
Variable weight apnea (VWT)Men145--William Winram2013-09-03Sharm el-Sheikh, Egypt
Variable weight apnea (VWT)Women127--Natalia Molchanova2012-06-06Sharm el-Sheikh, Egypt
No-limits apnea (NLT)Men214--Herbert Nitsch2007-06-14Spetses, Greece
No-limits apnea (NLT)Women160--Tanya Streeter2002-08-17Turks and Caicos
Static apnea (STA)Men--11 min 35 secStéphane Mifsud2009-06-08Hyères, Var, France
Static apnea (STA)Women--9 min 02 secNatalia Molchanova2013-06-29Belgrade, Serbia
Dynamic apnea with fins (DYN)Men-281-Goran Čolak2013-06-28Belgrade, Serbia
Dynamic apnea with fins (DYN)Women-234-Natalia Molchanova2013-06-28Belgrade, Serbia
Dynamic apnea without fins (DNF)Men-225-Goran Čolak2013-11-21Pančevo, Serbia
Dynamic apnea without fins (DNF)Women-182-Natalia Molchanova2013-06-27Belgrade, Serbia

CMAS recognized world records[edit]

As of July 2014, the CMAS recognized world records are:[10]

DisciplineGenderDepth [m]Distance [m]TimeName/CountryDatePlaceStatus
Constant weight with fins (at sea)Men97--Davide Carrera, Italy2014-06-21Salina, ItalyWaiting approval
Dynamic apnea with fins in Olympic pool (fresh water)Women-237.80-Ilaria Bonin, Italy2013-08-07Kazan, RussiaWaiting approval
Static apneaMen--10:05Branco Petrovic, Serbia2012-10-01Antalya, TurkeyWaiting approval
Static apneaWomen--07:30Veronika Dittes, Austria2012-10-01Antalya, TurkeyWaiting approval
Jump blue apnea with fins (at sea)Women-168.69-Ilaria Bonin, Italy2012-10-31Kemer, Antalya, TurkeyWaiting approval
Jump blue apnea with fins (at sea)Men-185-Michele Giurgola, Italy2012-10-31Kemer, Antalya, TurkeyWaiting approval
Jump blue apnea with fins (at sea)Men-185-Xaier Delpit, France2012-10-31Kemer, Antalya, TurkeyWaiting approval
Variable weight apnea without fin (at sea)Men81--Devrim Cenk Ulusoy, Turkey2012-09-26Kas, Antalya, TurkeyWaiting approval
Free immersion apnea without fin (at sea)Men81--Devrim Cenk Ulusoy, Turkey2012-09-25Kas, Antalya, TurkeyWaiting approval
Constant weight with fins (at sea)Men94--Homer Leuci, Italy2012-09-15Soverato, ItalyWaiting approval
Variable weight apnea with fin (at sea)Men131--Homer Leuci. Italy2012-09-11Soverato, ItalyWaiting approval
Constant weight with fins (at sea)Women70--Şahika Ercümen, Turkey2011-11-10Dahab, EgyptApproved
Variable weight apnea without fin (at sea)Women60--Şahika Ercümen, Turkey2011-11-10Dahab, EgyptApproved
Constant weight with fins (fresh water)Men70--Michele Tomasi, Italy2011-10-02Trento, ItalyApproved
Constant weight with fins (at sea)Men87--Devrim Cenk Ulusoy, Turkey2011-10-02Kas/Antalya, TurkeyApproved
Free immersion apnea without fin (at sea)Men80--Devrim Cenk Ulusoy, Turkey2011-10-01Kas/Antalya, TurkeyApproved
Constant weight with fins (at sea)Men86--Homer Leuci, Italy2011-09-09Calabria, ItalyApproved
Jump blue apnea with fins (at sea)Men-175.66-Michele Fucarino, Italy2011-09-04Tenerife, SpainApproved
Jump blue apnea with fins (at sea)Women-158.54-Ilaria Bonin, Italy2011-09-04Tenerife/SpainApproved
Static apneaMen--09:32Branco Petrovic, Serbia2011-09-02Tenerife, SpainApproved
Static apneaWomen--06:38Sophie Jacquin, France2011-09-02Tenerife, SpainApproved
Dynamic apnea with fins in Olympic pool (fresh water)Men-250-Goran Colak, Croatia2011-09-01Tenerife, SpainApproved
Jump blue apnea with fins (at sea)Men-171.45-Alfredo Roen, Spain2010-10-10Tenerife, SpainApproved
Jump blue apnea with fins (at sea)Women-144-Monica Barbero, Italy2010-10-10Tenerife, SpainApproved
Dynamic apnea with fins in Olympic pool (fresh water)Men-248.52-Goran Colak, Croatia2010-09-13Zagreb/CroatiaApproved
Dynamic apnea with fins in Olympic pool (fresh water)Women-205.44-Ilaria Bonin, Italy2010-06-12Lignano, ItalyApproved
Constant weight with fins (at sea)Men84--Homer Leuci, Italy2009-10-04Andora, ItalyApproved
Constant weight with fins (at sea)Men83.1--Devrim Cenk Ulusoy, Turkey2008-10-26Antalya, TurkeyApproved
Jump blue apnea with fins (at sea)Men-159.54-Devrim Cenk Ulusoy, Turkey2008-09-05Antalya, TurkeyApproved
Constant weight with fins (fresh water)Women57--Tanya Streeter, USA1998-12-28Ocala, Fl, USAApproved
Constant weight with fins (at sea)Women67--Tanya Streeter, USA1998-09-19S.Maria Nevernese, ItalyApproved
Constant weight with fins (fresh water)Men55--Eric Cherrier, France1997-08-09Lac De Sainte Croix Du VerdonApproved

Recreational[edit]

Freediving is also a recreational activity, celebrated as a relaxing, liberating and unique experience significantly different from scuba diving. The advantages freediving has over scuba diving are:

Experienced freedivers can often go as deep as scuba divers, and sometimes deeper.[clarification needed] Recreational freediving is practiced by many people ranging from the average snorkeler to the professional freediver. Recreational freediving is also frequently practiced in freshwater springs due to excellent visibility and underwater caverns.[citation needed] This type of freediving into spring caverns and caves is very different from diving in the ocean. Even though every spring cave is unique, these are the general differences:

The time that a freediver can spend underwater on a single excursion is severely restricted in comparison with scuba, and a considerably greater level of fitness is required for longer breathhold times.

Physiology[edit]

The human body has several reflex oxygen-conserving adaptations that manifest under diving conditions. The adaptations include:

Techniques[edit]

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.[11] Various athletes attempt to accomplish this in various ways. By and large most divers rely on increasing fitness by increasing lung capacity, by `packing´ and hyperventilating, both of which increase lung oxygen stores.[12] Needless to say, simple breath-holding is highly effective for increasing lung capacity. In addition, training is allocated to enhance blood and muscle oxygen stores, to a limited extent. A substantial proportion of performance is the result of metabolic suppression and redistribution of blood oxygen stores, the so-called dive response. Increasing lung capacity has some draw-backs, however.

Some deep experimental divers, such as Sebastien Murat, model their diving on evolutionary-vetted[clarification needed] universal diving strategies employed by diving animals, especially mammals. He dives, almost exclusively, depending on objectives and circumstance on `empty´ lungs or after a passive exhale[citation needed]. This has the effect of greatly accentuating the dive response, which though greatly conserving oxygen stores and redistributing it to more vital organs sacrifices as much as 50% or more of the body's oxygen stores[citation needed]. The analogy is akin to an economical car with a small fuel tank versus a fuel guzzling pick-up truck with a large tank[clarification needed]. Another advantage is that it allows skeletal muscles (and possibly heart muscle?) to `learn´ to increase their myoglobin, i.e. locked-in oxygen stores vs convection (hemoglobin) stores, thereby delaying a shift to anaerobic energy stores and, hence, excessive muscle fatigue[citation needed]. Like all things it requires a period of adaptation but can be greatly fast-tracked with an in-depth understanding of the mechanisms involved[citation needed][clarification needed].

An additional benefit of this technique is that it permits reaching greater levels of hypoxia without excessive respiratory discomfort, due to a build-up of metabolic CO2[citation needed]. Indeed, less overall CO2 is produced since the oxygen stores are much reduced, thereby allowing more frequent reaching of incursion into acute levels of adaptive hypoxia and, hence performance improvements[citation needed]. This would seem to reduce the safety margin before incurring an undeserved loss of consciousness but this problem can be circumvented to a significant extent because diving on empty lungs substantially lowers metabolic rate and results in a more pronounced brain cooling effect, both of which offer some little recognized benefits[citation needed]. Specifically, the critical (time-dose) hypoxia tolerance increase the greater the cooling and the lower the metabolic rate, allowing reaching greater levels of hypoxia for longer and without ill effects, i.e., loss of consciousness Murat pers obs[original research?][citation needed].) In non-ballast assisted dives it also minimize the effort of descend to the absolute minimum, since buoyancy is reduced. This helps conserve precious oxygen stores and accentuate the dive response. In addition, the `empty lung´ approach also limits the risk of a reflex reversal of the dive response during ascent[citation needed], which is triggered by lung re-expansion. This permits swimming and even sprinting with no in-dive penalty[citation needed]. Basically, work effort becomes uncoupled from oxygen consumption[citation needed], i.e., dynamic times become comparable to static times. This is important because oxygen consumption is normally a function of swimming speed, i.e., hydrodynamic drag scaling effects, but in this instance this approach allows complete `escape´ from drag related effects, i.e., there is no O2 penalty for swimming fast or working hard[citation needed], and the fundamental drag equation, as it relates to oxygen consumption, becomes meaningless[clarification needed][citation needed].

To side-step this lung re-expansion reflex problem, something that occur over the last 30 m of ascent, exhale over the last 5 or so meters. Though this may lock-down the dive response, it would require exhaling from depths of at least 20m to completely side-step. Moreover, it cannot avoid the fact that a substantial amount of oxygen is lost by exhaling, and at the worse possible moment, when the diver is already low on oxygen. That apart, buoyancy is lost, which renders this full lung approach somewhat illogical in the first instance. An empty lungs approach offers the additional advantage of substantially lowering nitrogen loads, which in very deep-diving, would otherwise result in nitrogen narcosis, poor decision making ability, potentially, loss of consciousness, and a high probability of decompression illness[citation needed]. Though diving on empty lungs greatly mitigates this problem, instead of doing a safety-stop during the final stages of ascent,[citation needed] Murat goes into pre-descent in-water static breath-hold procedure[clarification needed] lasting from 20-50", depending on the stress levels (the greater the pre-dive stress, e.g., the more extreme the dive, the shorter the necessary time to full manifest a pronounced dive response). This early, say, sacrificial strategy of allowing time for a metabolic `shut-down´/lock-down paradoxically does not penalize actual dive time or depth reached but paradoxical substantially enhances performance.[citation needed] Moreover, it reduces nitrogen uptake which has the advantage of `locking-in´ the dive response and reducing metabolism,[citation needed] despite the activity of descent, and greatly limiting nitrogen absorption, especially during the steep (shallow 0-20m) part of the pressure gradient. However, it must be noted that such techniques generally require considerable mental control, physiologic understanding, self-awareness, and pressure adaptation and, beyond depth of about 60 or so meters, the use of sinus and ear cavity-flooding, since there exists essentially no air for pressure compensation of the uppermost airways.[citation needed] Centrally, it requires a high degree of metabolic control to potentiate the dive response;[citation needed] genetic factors and an excessively elevated pre-dive metabolism may limit and negate an individual's ability to fully tap-into such techniques.[citation needed]

Training[edit]

Training for freediving can take many forms and be performed on land.

One example 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, the participant then initiates a walk for as far as they can, until it becomes necessary to breathe again. Athletes can do close to 400 meters in training this way.[citation needed]

This form of training is good for accustoming muscles to work under anaerobic conditions, and for tolerance to CO2 build-up in the circulation. It is also easy to gauge progress, as increasing distance can be measured.

Before competition attempt, freedivers perform preparation sequence, which usually consists of physical stretching, mental exercise and breath exercise. It may include sequention of variable length static apnea, special purging deep breaths, hyperventilation. Result of preparation sequence is slower metabolism, lower heart rate and breath rate, lower level of CO2 in bloodstream[13] and overall mental equilibrium. Failing ordinary warning signals or crossing mental barrier by strong will may lead to shallow water blackout or deep water blackout.[14][15] Trained freedivers are well aware of this and will only dive under strict and first aid competent supervision.[16] However this does not eliminate the risk of deep or shallow water blackout. All safe freedivers have a 'buddy' who accompanies them, observing from within the water at the surface. Due to the nature of the sport, any practice of freediving must include strict adherence to safety measures as an integral part of the activity, and all participants must also be adept in rescue and resuscitation. Without proper training and supervision, freediving/apnea/breath-hold diving is extremely dangerous. The death of Nicholas Mevoli, a diver from New York, highlights the dangers of freediving. He died on 17 November 2013 after completing a dive to a depth of 72 metres.[17]

In fiction[edit]

See also[edit]

References[edit]

  1. ^ Ivanova, Desislava; Nihrizov, Hristo; Zhekov, Orlin (1999). "The Very Beginning". Human Contact With the Underwater World. Think Quest. Retrieved 2009-09-06. 
  2. ^ Sandra Hendrikse and André Merks (12 May 2009). "Diving the Skafandro suit". Diving Heritage. Retrieved 2009-10-16. 
  3. ^ Lundgren, Claus EG; Ferrigno, Massimo (eds). (1985). Physiology of Breath-hold Diving. 31st Undersea and Hyperbaric Medical Society Workshop. UHMS Publication Number 72(WS-BH)4-15-87. Undersea and Hyperbaric Medical Society. Retrieved 2009-04-16. 
  4. ^ Rahn, H.; Yokoyama, T. (1965). Physiology of Breath-Hold Diving and the Ama of Japan.. United States: National Academy of Sciences – National Research Council. p. 369. ISBN 0-309-01341-0. Retrieved 2009-04-16. 
  5. ^ Galili, Ehud; Rosen, Baruch (2008). "Ancient Remotely-Operated Instruments Recovered Under Water off the Israeli Coast". International Journal of Nautical Archaeology (Nautical Archaeology Society) 37 (2): 283–94. doi:10.1111/j.1095-9270.2008.00187.x. 
  6. ^ Frost, FJ (1968). "Scyllias: Diving in Antiquity". Greece and Rome (Second Series) (Cambridge University Press) 15 (2): 180–5. doi:10.1017/S0017383500017435. 
  7. ^ Thucydides (431 BCE). History of the Peloponnesian War. 
  8. ^ a b c d McKie, N (2004). "Freediving in cyberspace.". Journal of the South Pacific Underwater Medicine Society. 34: 101–3. Retrieved 2013-10-05. 
  9. ^ AIDA International. "World Records". Retrieved 2014-07-19. 
  10. ^ Confédération Mondiale des Activités Subaquatiques. "Apnoea Records". Retrieved 2014-07-19. 
  11. ^ Schagatay E (2009). "Predicting performance in competitive apnoea diving. Part I: static apnoea.". Diving Hyperb Med 39 (2): 88–99. PMID 22753202. Retrieved 2013-10-06. 
  12. ^ Simpson, G; Ferns, J; Murat, S (2003). "Pulmonary effects of ‘lung packing’ by buccal pumping in an elite breath-hold diver.". Journal of the South Pacific Underwater Medicine Society 33: 122–126. Retrieved 2013-10-06. 
  13. ^ Neal W. Pollock, Richard D. Vann, Edward D. Thalmann and Claus EG Lundgren. (1997). "Oxygen-Enhanced Breath-hold Diving, Phase I: Hyperventilation and Carbon Dioxide Elimination". In: EJ Maney, Jr and CH Ellis, Jr (Eds.) Diving for Science...1997. Proceedings of the American Academy of Underwater Sciences (17th Annual Scientific Diving Symposium). Retrieved 2009-04-16. 
  14. ^ Lindholm P, Pollock NW, Lundgren CEG (2006). Breath-hold diving. Proceedings of the Undersea and Hyperbaric Medical Society/Divers Alert Network 2006 June 20–21 Workshop.. Durham, NC, United States: Divers Alert Network. ISBN 978-1-930536-36-4. Retrieved 2008-04-30. 
  15. ^ Lundgren, Claus EG; Ferrigno, Massimo (eds). (1985). Physiology of Breath-hold Diving. 31st Undersea and Hyperbaric Medical Society Workshop. UHMS Publication Number 72(WS-BH)4-15-87. Undersea and Hyperbaric Medical Society. Retrieved 2009-04-16. 
  16. ^ Fitz-Clarke, JR (2006). "Adverse events in competitive breath-hold diving.". Undersea Hyperb Med 33 (1): 55–62. PMID 16602257. Retrieved 2013-10-06. 
  17. ^ Skolnick, Adam (November 17, 2013). "A Deep-Water Diver From Brooklyn Dies After Trying for a Record". The New York Times. Retrieved November 30, 2013. 

Further reading[edit]

External links[edit]