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Free-diving

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Free-diving refers to various aquatic activities that share the practice of breath-hold diving. Examples include breathhold spearfishing, freedive photography, Apnea competitions and, to a degree, snorkeling. The activity that garners the public's attention is Competitive Apnea, considered an extreme sport, where divers attempt to attain great depths, times or distances on a single breath and without direct assistance of a breathing apparatus.

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[edit] Description

Freediving refers to a technique that is used with various aquatic activities. While in general all aquatic activities that include breath-hold diving might be classified as a part of freediving, some sports are more accepted than others. Examples of recognised freediving activities are (non-) competitive freediving, (non-) competitive spearfishing, freedive photography and mermaid shows. Less recognised examples of freediving include, but is not limited too, synchronised swimming, underwater rugby, underwater hockey, underwater hunting other than spearfishing and snorkeling. The discussion remains if freediving is only a synonym for breath-hold diving or it does describes a specific group of underwater activities. Freediving is often strongly associated with competitive breath hold diving or *Competitive Apnea*. It is considered to be an extreme sport wherein divers attempt to attain great depths, times, or distances on a single breath and without the assistance of breathing apparatus like SCUBA. The following remainder of this article will only discuss competitive freediving as an athletic sport.

[edit] Competitive Freediving

Competitive freediving is currently governed by two world associations: AIDA International and CMAS. Most types of competitive freediving have in common that it is an individual sport based on the best individual achievement. Exceptions on this rule is the bi-annual World Championship for Teams, held by AIDA International, where the combined score of the team members makes up the teams total points. There are currently nine disciplines used by official governing body’s and a dozen disciplines that are only practiced locally. In this article, the recognised disciplines of AIDA International 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 is recognised any longer. The disciplines of {{AIDA International]] can be done both in competition as in an record attempt with the exception of Variable Weight and No limits who are both only done as record attempts. Following official disciplines are recognised by (AIDA), (CMAS) or both.

[edit] Pool Disciplines

  • Static Apnea is timed breath holding and is usually attempted in a pool. (AIDA)
  • Dynamic Apnea with fins. This is underwater swimming in a pool for distance. For this discipline the athlete can choose if he uses bi-fins or the monofin. (AIDA), (CMAS)
  • Dynamic Apnea without fins. This is underwater swimming in a pool for distance without any swimming aids like fins. (AIDA)

[edit] Depth Disciplines

The depth of the athlete is for all AIDA disciplines announced before the dive. This is accepted practice for both competitions as record attempts.

  • Constant Weight with fins. The athlete has to dive to the depth following a guideline he or she is not allowed to actively use during the dive. The ‘constant weight’ (“poids constant”) refers to the fact that the athlete is not allowed to drop the weights during the dive. Both bi-fins and mono-fin can be used during this discipline (AIDA).
  • Constant Weight without fins follows the identical rules as Constant Weight with fins, except no swimming aids as fins are allowed. This discipline is the youngest discipline within competitive freediving and is recognised by AIDA International since 2003.(AIDA)
  • Free Immersion is the discipline where the athlete uses the guideline to pull him or herself down to depth and back to the surface. It is known for its ease compared with the Constant Weight disciplines, while it is still not allowed to release weights (AIDA).
  • Variable Weight is a record discipline that uses a weighted sled for descent. Athlete returns to the surface by pulling themselves up along a line or swimming while using their fins (AIDA).
  • No Limits is a record discipline that allows the athlete to use any means of breath-hold diving to depth and return to the surface as long as a guideline is used to measure the distance. Most divers use a weighted sled to dive down and use an air-filled bag to return to the surface (AIDA).
  • "The Cube" is also known as "Jump Blue" and is a discipline where an athlete has to descend to 15 meters and have to swim as far as possible in a cubic form of 15 x 15 meters. (CMAS)

Each organisation has its own rules on recognising an attempt. These can be found on the website from the respective organisations.

[edit] Physiology of Free-diving

The human body has several adaptations under diving conditions, which stem from the mammalian diving reflex. These adaptations enable the human body to endure depth and lack of oxygen far beyond normal.

The adaptations made by the human body while underwater and at high pressure include:

  • Bradycardia: Drop in heart pulse rate.
  • Vasoconstriction: Blood vessels shrink. Blood stream directed away from limbs for the benefit of heart, lungs and brain.
  • Splenic contraction: Releasing red blood cells carrying oxygen.
  • Blood shift: Blood plasma fills up blood vessels in the lung and reduces residual volume. Without this adaptation, the human lung would shrink and wrap into its walls, causing permanent damage, at depths greater than 30 meters.

[edit] Training

Training for free diving can take many forms, many of them out of water.

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.

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 diving, untrained free divers may hyperventilate, resulting in a lower level of CO2 in their lungs and bloodstream. This postpones the start of stimulation to the breathing centre of the brain, and thus delays the warning signals of running out of air. As the oxygen level of the blood is not increased by hyperventilation, this is very dangerous and may result in drowning. (For more detail refer to the articles shallow water blackout and deep water blackout.) Trained freedivers are well aware of this and will limit their immediate pre-dive breathing, typically to a maximum of two or three breaths taken slowly and deeply so as to maximize oxygen saturation whilst not depressing blood CO2 levels. However this does not, of itself, eliminate the risk of deep or shallow water blackout and diving with a 'buddy' who remains observing at the surface is the standard practice.

[edit] Official World Records as of 2006-09-24 (AIDA)

  • Constant Weight, without fins
  • No limit
    • women: Tanya Streeter (Cayman Islands), -160 meter
    • men: Herbert Nitsch (Austria), -183 meter <ref>Patrick Musimu did 209 meters in No Limit, this was done in training without an AIDA judge present.</ref>
  • Free Immersion
    • women: Natalia Molchanova (Russia), -80 meter
    • men: Martin Štìpánek (Czech Republic), -106 meter

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[edit] Free-diving in Fiction

  • In the Canadian television series Corner Gas, the character Karen Pelly (Tara Spencer-Nairn) was a professional free-diver, ranking fifth in Canada with a personal best of over six minutes.
  • The Big Blue (1988) starring Rosanna Arquette, Jean Reno, and Jean Marc-Barr is a romance film about two world-class free-divers. (Fictional)

[edit] Some famous Competitive Apnea Divers

   

[edit] See also

[edit] External links

da:Fridykning de:Apnoetauchen fr:Apnée (sport) id:Selam bebas it:Immersione in apnea nl:Vrijduiken ja:フリーダイビング no:Fridykking pl:Freediving ru:Фри-дайвинг sk:Nádychové potápanie fi:Vapaasukellus sv:Fridykning

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