FREEDIVING

29.05.2008

Freediving is diving holding one's breath, without any breathing apparatus. In competitive freediving there are several sub-disciplines, five of these depth-related. Out objective is to achieve Finnish national records in all five depth disciplines.
 

SAFETY

Freediving is a safe sport if certain safety procedures are always followed. There are, however inherent risks involved that one might not think of without appropriate instruction and guidance. The most important rule is to never dive without a buddy who is familiar with safety and rescue practices. This rule remains whether you dive in a shallow pool or in the ocean. Nonetheless, diving for depth does place additional demands on the abilities of the safety divers. Freediving should always be started under the guidance of more experienced divers, for example by taking a freediving course.
 

FREEDIVING DEPTH DISCIPLINES:

Constant Weight

The diver descends to his target depth using fins for assistance. The diver is allowed to use weights, but the amount of weight must not change during the dive: everything taken down must be brought back up. Hence the term "Constant Weight". 

The present Finnish record is 86 metres, held by Timo Kinnunen since 2005.
 

Constant Weight Without Fins

As above, but without using fins for assistance.

Present Finnish record is 60 metres, by Topi Lintukangas in 2002.

 

Free Immersion

A depth-diving discipline in which the diver descends by pulling himself along a rope. Especially good in familiarising oneself with new depths or e.g. resolving equalization problems, because it is easier to regulate one's speed than in the other disciplines.

Present Finnish record is 60 metres, by Antero Joki in 2008.

 

Variable Weight

In this discipline the descent is done with the help of a large weight, or "weight sled". Return to the surface takes place by swimming or pulling along a rope.

No official Finnish record exists. The deepest known dive is 64 metres, by Timo Kinnunen in 2003.

 
No Limits

Like Variable Weight, but assisting equipment is used also for the ascent, e.g. a lifting bag.

No official Finnish record. Deepest know dive 65 metres, by Timo Kinnunen in 2003.

 
 

Current Finnish national records
 

Some freediving vocabulary

Equalization

Air-filled compartments in a diver’s body cannot withstand a very high pressure difference compared to the external pressure. Therefore, as depth and water pressure increases, air must be added to the middle ear, sinuses and mask to decrease the difference in pressure. This is called equalization, and it is the depth-limiting factor for many freedivers.
 

Lanyard

The lanyard is a safety rope used to attach the freediver to the descent line. The lanyard prevents the freediver from getting lost from the descent line, especially in poor visibility. It can also be used to pull the diver back to the surface in an emergency.
 

Sled

A heavy device that slides along the descent line. It is used by the diver to descend in the no limits and variable weight disciplines.
 

Monofin

A single wide fin, that is attached to both feet.  The swimming technique with this kind of fin is like a clumsy version of a dolphin swimming.

Freefall

As depth and water pressure increase, the lungs and wetsuit are compressed. This causes the diver’s buoyancy to decrease with depth. Once the diver is deep enough he/she can cease all movement and begin to sink passively. This stage of the dive is called the freefall, and according to many freedivers, it is the most pleasurable part of the dive.

 
 

Diving reflex

Heart rate and blood perfusion of the muscles decrease during a freedive. Blood circulation is concentrated in the organs that are most sensitive to hypoxia (deficiency of oxygen). These changes decrease oxygen consumption, and together they are called the diving reflex (or diving response). The diving reflex is especially pronounced in seals and other marine mammals, but it affects human divers too. The human diving reflex is much weaker, however, compared to those mammal species that are adapted to diving.

 

Residual volume

The strucure of the human lung and chest cavity prevents the lungs from completely emptying. Even after a maximal exhale there will be on average about 1,5 litres of air left in the lungs. This volume is called the residual volume. This makes for example equalizing challenging during a deep freedive.