There’s a small group of dedicated freedivers who have created world championship events with eight breath-holding categories. The competitions are produced by the AIDA.
According to AIDA – the Association Internationale pour le Développement de l’Apnée describes the eight Freediving disciplines:
No Limit (NLT) – The freediver descends with the help of a ballast weight and ascends via a method of his choice. No limit is the absolute depth discipline. Going down with a sled, and going back up with a balloon, a diving suit or a vest with inflatable compartments, or whatever other means.
Variable Weight (VWT) – The freediver descends with the help of a ballast weight and ascends using his own strength: arms and/or legs, either by pulling or not pulling on the rope. Variable weight is the first of both depth disciplines using a sled to go down in the water. Old sleds was descending “head first”, like presented in the famous Luc Besson’s movie “Le Grand Bleu”, but new sleds descending “feet first” are now generalized.
Constant Weight (CWT) – The freediver descends and ascends using his fins/monofin and/or with the use of his arms without pulling on the rope or changing his ballast; only a single hold of the rope to stop the descent and start the ascent is allowed. Constant weight is the common sportive depth discipline of freediving, because of the specific fins or monofins used in it. Constant weight is one of the three disciplines considered for the international competitions by team, with Static apnea and Dynamic with fins.
Constant Weight Without Fins (CNF) – The freediver descends and ascends under water using only his own muscle strength, without the use of propulsion equipment and without pulling on the rope. Constant weight without fins is the most difficult sportive depth discipline, because of absolutely no propulsing material to go down in the water. This category needs a perfect coordination between propulsing movments, equalization, technique and buoyancy.
Free Immersion (FIM) – The freediver dives under water without the use of propulsion equipment, but only by pulling on the rope during descent and ascent. Free immersion is the sportive depth discipline with the purest sensations, because of the speed of the water in the body, and the power of each pull on the rope as only mean of propulsion. Performances could be done the head first during the descent, or the feet first, depending equalization facilities of each freedivers… Some of them also even use mixed solutions.
Dynamic With Fins (DYN) – The freediver travels in a horizontal position under water attempting to cover the greatest possible distance. Any propulsion aids other than fins or a monofin and swimming movements with the arms are prohibited Dynamic with fins is the most typical of both disciplines measuring the distance in freediving, because of the specific means of propulsion : long fins or monofin. Performances could only be recognized in swimming-pools with a minimum length of 25 meters, and are sometimes considered in national or indoor’s ‘combiné’, with the Static apnea.
Dynamic Without Fins (DNF) – The freediver travels in a horizontal position under water attempting to cover the greatest possible distance. Any propulsion aids are prohibited. Dynamic without fins is the most natural of both disciplines measuring the distance for many freedivers, because it doesn’t need any propulsing material, but a very good technique. Performances also could only be recognized in pools with a minimum lenght of 25 meters, and are greatly appreciated from “old-swimmers”.
Static Apnea (STA) – The freediver holds his breath for as long as possible with his respiratory tracts immerged, his body either in the water or at the surface. Static apnea is the only discipline measuring the duration, and one of the three disciplines considered for the international competitions by team, with Constant weight and Dynamic with fins. Performances could be done and recognized in both pool or open water (sea, lake, river, etc).
Article courtesy of www.aidainternational.org
Video: William Trubridge breaking a world record, and what freedivers do for fun.