What is Freediving - Constant Weight Discipline Explained
Constant Weight : Description
Widely regarded as the most prestigious of the freediving disciplines, Constant Weight Apnoea requires the freediver to ascend and descend along the dive-line without touching it (except once at the bottom to turn) and without altering their weight during the dive. They can, however, use fins to assist them. Most competitive CWT diving is now done with a monofin (see below) but bifins can also be used, and usually are for freedivers who are learning the sport.
When using a monofin, the diver usually puts one or both arms over the head and employs a 'dolphin kick' to propel themselves through the water:
Although the monofin is very forgiving, achieving a truly powerful and efficient style takes a lot of practice and in the beginning, most freedivers use bifins for constant-weight. Bifins are generally less efficient than a monofin used with good technique but dives of more than ?????????m have still been made with them successfully. The usual technique for bifins is with long straight legs, relaxed ankles and arms held by the sides:
With both techniques, the diver will usually swim down to about 20 or 25m before entering a freefall which is made possible by the effect of the water pressure on the air in the lungs. This negative bouyancy has to be overcome on the way up, however.
Monofins come in all shapes and sizes, from the 'mermaid's tail' for children to the full carbon competition fin, usually custom-made for a particular athlete. A close fit is important to ensure efficient transfer of energy through the body to the fin itself (Except for the mermaid's tail).
Bifins, too, come in various different types. Those used for freediving are usually long and can be made of plastic, fibreglass or carbon fibre, though short fins will also do in the beginning.
For competition and for deep dives in training, CWT freedivers use a lanyard to ensure that they don't become separated from the dive-line. For CWT the lanyard can be worn around the waist or on the wrist since these points have minimal movement relative to the line during the dive.
Because the arms are not used during a CWT dive, a mask can be used without too much disruption to the stroke from the need to equalise the ears. Despite this, many competitive freedivers use a noseclip and fluid goggles, or just a noseclip to free up their hands for greater streamlining.
CWT World Records
Women - Natalia Molchanova (RUS) 101m
Men - Alexey Molchanow (RUS) 128m