What is Freediving - No Limit Discipline Explained
No Limit: Description
No Limits apnea is one of two, with Variable Weight, non-competition disciplines for which world records can be set. As the name suggests, the No-Limits freediver can use any means they like to descend as deep as possible and ascend to the surface again. In the early days of competitive freediving this was the main discipline that was practiced. Divers would typically use a heavily weighted sled to descend and then a gas filled baloon to ascend again, at speeds of around 2m/s. More recently, problems with the gas-filling system at depth and the inability of divers to operate it properly because of the effects of nitrogen narcosis has led to a change in the way that very deep NLT dives are conducted. For the current men's world record, a winch was used to retrieve the sled at speeds in excess of 5m/s. Of all the freediving disciplines, NLT is undoubtedly the most dangerous. In fact, because of the dangers involved and a number of recent high profile accidents, none of the international freediving bodies will currently ratify NLT record attempts. Outside of record-breaking, it is often used by freedivers in training for other disciplines to help practice equalisation techniques and adapt to new depths.
No Limit: Technical Considerations
Although from the outside it may look as if the NLT freediver has nothing to do except hold on to the sled and hold their breath, NLT is actually one of the most technical disciplines in freediving. Aside from the problems of equalising at depths in excess of 150m and descent speeds of 5m/s or more (which are considerable) the diver must learn to deal with the effects of pressure on their body at depth and as they return to the surface. A NLT record attempt is really a team effort, with crew on the surface operating the sled and the winch and a huge number of individuals in a supporting role.
No Limit: Specialist Equipment
NLT is by far the most equipment intensive of the freediving disciplines. Aside from the obvious- the sled and winch or gas-balloon system, a range of advanced safety systems including underwater scooters, scuba safety at depths as great as 125m (in itself a risky and technical undertaking) and backup in case the primary ascent systems fail. The NLT diver is almost entirely reliant on their equipment and safety team since an ascent to the surface under their own power from the bottom is usually impossible. In the video above you might notice that the diver is using, of all things, a coke bottle to help with equalisation. This is used as a reservoir of air to be used at depth when conventional methods of equalisation fail.
IMPORTANT: No Limits Freediving is very very dangerous. It should not be attempted by anyone but the most experienced freediviers in the world. It should always be carried out under supervision by a qualified instructor using proper equipment and safety techniques.
Remember, Never, Ever Freedive alone.
NLT World Records
Women - Tanya Streeter (USA) 160m
Men - Herbert Nitsch (AUT) 214m