The term "Apnoea" designates a sports event where the athlete holds his breath keeping the face below the surface of the water. Free diving is a technique used in various aquatic activities. While in general all aquatic activities that include breath-hold diving might be classified as a part of free diving, some sports are better established than others. Examples of recognized freex diving activities are (non-) competitive free diving, (non-) competitive spear fishing and free diving photography. Less recognised examples of free diving include, but are not limited to, synchronised swimming, underwater rugby, underwater hockey, underwater target shooting, underwater hunting other than spear fishing, and snorkelling. The discussion remains whether free diving is only a synonym for breath-hold diving or whether it describes a specific group of underwater activities. Free diving is often strongly associated with competitive breath-hold diving or Competitive Apnoea.
The following official disciplines are recognized by CMAS and the organizing country must select among those ones. That will allow the countries which do not have open water to organize a championship in pool only.
On the other hand, National competitions may be open to international participants. In this case the national federations should inform CMAS 2 months before the date of the competition. Then CMAS will announce that on the CMAS web page as well as the national federation. It is strongly recommended that the Main Judge for the competition be an International CMAS Judge.
Maximum number of athletes per country and per gender to 6 for each discipline. National team ranking is expected to be based on the total number of medals according to the Olympic standards.
Competitive free diving
Competitive free diving is currently governed by various associations and one of them is CMAS. Most types of competitive free diving have in common that it is an individual sport based on the best individual achievement. There are currently eleven disciplines in CMAS. All disciplines can be done by both men and women. The disciplines can be done both in competition and as a record attempt.
But currently only Dynamic with Fins and Jump Blue Apnoea has got approved rules for championships and Constant Weight Apnoea for record attempts. The commission has done the draft rules for other disciplines and those are to be finished t the next commission meeting.
A. Pool disciplines
- Static Apnoea: Static Apnoea is an event where the athlete aims at performing a maximum duration apnoea minimally over a time declared beforehand and if possible going beyond this time. The event is conducted in a swimming-pool or in open water.
- Dynamic Apnoea With or Without Fins: Dynamic apnoea is an event where the athlete aims at covering the maximal horizontal distance by swimming in apnoea with or without fins. The event can be conducted in a swimming-pool or in open water and with the use of fins (bi-fins or monofin) or without. When fins are used, they must be powered only by the muscular power of the athlete, without use of any mechanism, even if the latter is activated by the muscles.
- Speed-Endurance Apnoea: Speed-Endurance apnoea is an event where the athlete aims at covering a fixed distance at the minimum possible time. The event is conducted in a swimming-pool and is swum in fractions of a pool length alternating apnoea swimming with passive recovery at the pool's ends.
The event is swum with the use of fins (bi-fins or monofin). The fins must be powered only by the muscular power of the athlete, without use of any mechanism, even if the latter is activated by the muscles.
The typical distances of speed-endurance apnoea are 100 m and 400m but competition on other distances may be organized, including relays.
B. Depth disciplines
- The Jump Blue: The Jump Blue is an event where the athlete must cover the maximum distance in apnoea around a square of 15 (fifteen) meters side situated in a depth of 10 (ten) meters. The event takes place in open water (sea or lake) and the use of fins (bi-fins or monofin) is mandatory. The fins must be powered only by the muscular power of the athlete, without use of any mechanism, even if the latter is activated by the muscles.
- Constant Weight Apnoea With or Without Fins: The Constant Weight Apnoea is an event where the athlete must cover the vertical distance in apnoea down to the declared depth without any change in his weight during the whole performance with or without fins.
The event takes place in open water (sea or lake) and the use of fins (bi-fins or monofin) or without fins depends on the type of the competition. When fins are used, they must be powered only by the muscular power of the athlete, without use of any mechanism, even if the latter is activated by the muscles.
- Free Immersion Apnoea: The Free Immersion Apnoea is an event where the athlete must cover the maximum vertical distance in apnoea to a declared depth without using ballast or fins.
The event takes place in open water (sea or lake) and the athlete is allowed to pull on the guiding rope. The use of any mechanism even if the latter is activated by the muscles of the athlete is prohibited.
- Variable Weight Apnoea With or Without Fins: The Variable Weight Apnoea is an event where the athlete must cover the vertical distance in apnoea along down to the declared depth with a guided ballast device and return back with his own power.
The event takes place in open water (sea or lake) and use of fins (bi-fins or monofin) is optional.
- Skandalopetra: Skandalopetra is an apnoea discipline with historical roots. The name comes from the Greek words "scandali" (trigger) and "petra" (stone).
It is precisely this stone which forms the basis of this discipline.
The athlete dives with the help of a stone (usually a marble slab) attached to a rope. Skandalopetra is a team event: one athlete dives and one is waiting at the surface. When the first athlete reaches the desired depth, the second starts hauling him up.
Recreational free diving
Free diving is also a recreational sport, celebrated as a relaxing, liberating, and unique experience. Many snorkelers may technically be free diving if they perform any sort of breath hold diving. It is important to stress the importance of training and supervision when making this association.
Like other water sports, free diving is associated with therapeutic properties. The experience of freedom in an underwater environment makes free diving somewhat of a personal and spiritual journey for many. Yoga is used by many practitioners to increase focus, breath, and overall performance.
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 what would be possible without the reflex.
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.
Training for free diving can take many forms and be done on the land.
One example is the apnoea 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 start walking and continue 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, performance-oriented free divers hyperventilate to a certain degree, 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 contribute to shallow water blackout and deep water blackout. Trained free divers are well aware of this and will only dive under strict and first aid competent supervision. However this does not, of itself, eliminate the risk of deep or shallow water blackout. All safe free divers have a 'buddy' who accompanies them, observing from within the water at the surface. Due to the nature of the sport, safety is an integral part of free diving, requiring participants to be adept in rescue and resuscitation. Without proper training and supervision, free diving/apnoea/breath-hold diving is extremely dangerous