Depth contains three separate disciplines, distance two and time one. These individual disciplines are explained below.
Static Apnea – STA
The Freediver holds their breath in a stationary position for as long as possible, face down in a pool. This is the only discipline that measures the dive duration rather than depth or distance. Performances can be recognised in both pool or open water.
Dynamic With Fins – DYN
This is a pool discipline. The freediver swims horizontally across the pool using fins – typically a mono fin, trying to cover the greatest possible distance. Performances are only recognised in pools with a minimum length of 25 meters.
Dynamic No Fins – DNF
This is a pool discipline. The Freediver swims horizontally across the pool without the use of fins covering the greatest possible distance. The Freediver uses an underwater breast stroke incorporating streamlining and ‘glide’ to obtain a balance of speed and relaxation. Performances are only recognised in pools with a minimum length of 25 metres.
Constant Weight With Fins – 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 No 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 propulsion material to go down in the water. This category needs a perfect coordination between propulsion movements, 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 freediver… Some of them also even use mixed solutions.