Women's champion, Natalia Molchanova of Russia, has also swum further than 200 m. Sietas also holds the Dynamic apnea without fins record at 183 m, beating Nitsch's 2001 distance of 134 m[2] by almost 50 m. Nitsch also held the world record in the Constant Weight event,[3] which is considered by many to be the classic free-diving discipline: the diver descends next to a line, not using the line and unaided by a sled, and must maintain a constant weight, meaning that no weight can be dropped for the return to the surface.

[6] Nitsch focused solely on the "No Limit" events after this, in which the record attempts fall outside of regulated competition.

Nitsch holds the No-Limits record and the title of "Deepest man on Earth"[1] in which the diver can make use of a weighted sled to descend as far as possible and uses an air-filled balloon or other buoyancy device to return to the surface.

[9] In 2012, Nitsch returned to the "No Limit" category in the waters off Santorini, Greece, with a project labeled "Extreme 800", aiming for a depth of 244 m (801 ft).

[10] Following extensive training using an innovative torpedo-type sled design of very high descend and ascend speed, on 6 June 2012, Nitsch managed to reach a depth of 253.2 meters (831 ft),[11] a Guinness World Record,[12] but ten minutes after the dive he began experiencing serious symptoms of decompression sickness.

Nitsch temporarily fell asleep due to nitrogen narcosis during the last part of the ascent (as opposed to through oxygen starvation), and woke up prior to reaching the surface.

Following a planned post-dive decompression, breathing medical oxygen at a shallow depth, he signaled to his support team that he felt much weaker than normal and his condition was assessed as critical enough to require an air transfer to a pre-alerted decompression chamber in Athens, where he received treatment.