This sport involves underwater swimming and diving without breathing apparatus. There are various specialities: static apnea in pools, dynamic apnea in pools, and deep apnea in open water. Deep apnea in turn is divided into: 1) constant weight apnea, in which the diver descends using his own muscle strength and ascends following a cable without touching it; 2) variable weight apnea, in which the diver descends on a sled weighing not more than 30 kg and releases it to return to the surface, using a cable for assistance if desired; 3) no-limits apnea, in which a sled of unrestricted weight is used for descent and an inflatable balloon for ascent. Upload videos or photos showing you in action and list your achievements.