What is Freediving - Variable Weight Discipline Explained
Variable Weight: Description
Variable Weight apnea is one of two with No Limit, non-competition disciplines for which world records can be set. As the name suggests, the Variable Weight freediver is allowed to change their weight during the dive - usually heavier on the way down, though they can, if they're stupid, do it the other way round! For record attempts and deep variable weight dives, a heavily weighted sled is usually used to take the diver to the bottom. The ascent is normally made by a combination of pulling on the line and finning.
As well as being a competitive event, variable weight can also be a great way to explore underwater, giving the freediver an easy descent and more time on the bottom, even at considerable depths:
Variable Weight: Technical Considerations
The main challenges for variable weight diving are breath-hold and equalisation. Deep variable weight dives can take the freediver well below 100m where finding air to equalise the ears can be a big problem. Because of the extra weight, the descent can also be very fast, meaning that good equalisation technique is essential. As well as this, the diver must ensure that they have enough oxygen remaining in the lungs and blood to make their own way back to the surface.
Variable Weight: Specialist Equipment
For deep variable weight dives, one of the most important pieces of equipment is the sled. These are often designed to be as hydrodynamic as possible to make the descent very quick. They may also weigh as much as 50kg. Divers will typically wear a very thick wetsuit (up to 7mm) even in warm water to increase their buoyancy on the ascent. For recreational variable weight, pretty much any heavy weight will do but it must be retrievable, without being attached to the freediver directly (that would be really dangerous). Usually the weight is rigged up to a rope which can then be pulled up afterwards.
IMPORTANT: Variable weight is potentially very dangerous. It should not be attempted by anyone who has not completed several freediving courses nor by anyone who does not consider themselves an experienced freediver. It should always be carried out under supervision by a qualified instructor using proper equipment and safety techniques.
Remember, Never, Ever Freedive alone.
VWT World Records
Women - Natalia Molchanova (RUS) 127m
Men - William Winram (CAN) 145m