No-limit apnea is an AIDA International freediving discipline of competitive freediving, also known as competitive apnea, in which the freediver descends and ascends with the method of his or her choice.[1] Often, a heavy metal bar or "sled" grasped by the diver descends fixed to a line, reaching great depths. The most common ascension assistance is via inflatable lifting bags or vests with inflatable compartments, which allow for rapid surfacing. The dives may be performed head-first or feet-first.
This form of diving is considered extremely dangerous by diving professionals.[2] No-limit apnea has claimed the lives of several divers.[3][4]
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