Free-diving

Free-diving

Free-diving, also known as breath-hold diving, is a form of underwater diving that relies on the diver's ability to hold their breath until resurfacing rather than using a breathing apparatus such as scuba gear. Free-diving is practiced both as a recreational activity and as a competitive sport.

History

Free-diving has ancient roots, with evidence of breath-hold diving dating back thousands of years. Ancient cultures, such as the Ama divers of Japan and Korea, have practiced free-diving for centuries to gather food and resources from the sea.

Physiology

The human body undergoes several physiological changes during free-diving, collectively known as the mammalian dive reflex. These changes include:

• Bradycardia: A slowing of the heart rate to conserve oxygen.
• Peripheral vasoconstriction: The narrowing of blood vessels in the extremities to redirect blood flow to vital organs.
• Blood shift: The movement of blood into the thoracic cavity to protect the lungs from the increased pressure at depth.

Techniques

Free-divers use various techniques to maximize their breath-hold time and depth, including:

• Relaxation and breathing exercises: To reduce oxygen consumption and increase lung capacity.
• Equalization techniques: Such as the Valsalva maneuver and Frenzel maneuver to equalize pressure in the ears and sinuses.
• Streamlining and efficient movement: To minimize energy expenditure while diving.

Disciplines

Competitive free-diving is divided into several disciplines, each with its own rules and objectives:

• Constant weight (CWT): The diver descends and ascends using fins or a monofin, without changing their weight.
• Free immersion (FIM): The diver pulls themselves down and up a rope without the use of fins.
• Static apnea (STA): The diver holds their breath for as long as possible while floating on the surface.
• Dynamic apnea (DYN): The diver swims horizontally underwater for the maximum distance on a single breath.

Safety

Safety is a critical aspect of free-diving. Divers must be aware of the risks, such as shallow water blackout and barotrauma, and take precautions to mitigate them. It is recommended to always dive with a buddy and to be trained in rescue techniques.

Equipment

While free-diving requires minimal equipment, certain gear can enhance performance and safety:

• Mask and snorkel: For visibility and breathing at the surface.
• Fins or monofin: To aid in propulsion.
• Wetsuit: For thermal protection and buoyancy.
• Weight belt: To achieve neutral buoyancy.

Organizations

Several organizations govern competitive free-diving and promote safety and education in the sport, including:

• AIDA International
• CMAS (Confédération Mondiale des Activités Subaquatiques)

See also

• Scuba diving
• Snorkeling
• Underwater sports