What is freediving

Diving on one breath — for depth, for distance, for time, or just to be quiet under water. This page is the sport in one sitting.

What it is

Freediving (apnea, from the Greek for “without breathing”) is diving without any breathing apparatus: you take one breath at the surface and come back on it. Humans have done it for food and pearls for thousands of years; as a sport it took shape in the 20th century and has had formal rules and world records since the 1990s.

It is as much a mental discipline as a physical one. A freediver trains the body to use oxygen slowly and the mind to stay calm while the urge to breathe grows. Most people who take a course are surprised by how far they get in a weekend — and by how quiet it is down there.

Disciplines

There are two families: what you do in a pool, and what you do in open water going down a line.

Pool

STA — Static apnea. Holding your breath lying face down in water, without moving. Measured in time. The purest test of relaxation; the world records are past 11 minutes.
DYN — Dynamic with fins. Swimming horizontally on one breath, with a monofin (or bi-fins). Measured in metres; the best swim more than 300 m.
DYNB — Dynamic with bi-fins. The same, but with two separate fins only — a separate discipline since 2019 (AIDA) because the technique is so different from the monofin.
DNF — Dynamic no fins. Breaststroke-like swimming on one breath, no fins at all. The most technical of the pool disciplines.

Depth

CWT — Constant weight. Down and up along a rope with a monofin (or bi-fins), without touching the rope or changing your weights. The classic depth discipline; records are past 130 m.
CWTB — Constant weight with bi-fins. The same with two fins.
CNF — Constant weight no fins. Down and up with nothing but your arms and legs. Regarded as the hardest of all.
FIM — Free immersion. Pulling yourself down and up the rope with your hands, no fins. Slow, calm, and the discipline most people start depth with.
VWT and NLT — Variable weight and No limits. Going down with a weighted sled and coming up by fins (VWT) or by a lift bag or the sled itself (NLT). Record-only disciplines, not held in competitions.

On Apneist Pro your personal bests are kept for the eight competition disciplines — STA, DYN, DYNB, DNF, CWT, CWTB, CNF and FIM — and measured against the national and world records.

Federations

AIDA International (Association Internationale pour le Développement de l'Apnée, 1992) — the body that formalised the sport: rules, judges, world records, world championships and the athlete rankings. Its education has four levels (AIDA 1–4) and instructor courses.
CMAS (Confédération Mondiale des Activités Subaquatiques, 1959) — the world underwater federation, which runs its own freediving championships and records, with slightly different rules (for example, its own set of pool disciplines and a different way of judging the surface protocol). Many national federations in Europe are CMAS members.
Schools and systems — Molchanovs, PADI, SSI, Apnea Academy and others teach freediving with their own course structures. Their certificates are recognised by clubs and centres everywhere; competitions, though, are held under AIDA or CMAS rules.

Apneist Pro reads official results straight from both federations: your AIDA athlete page (bests, rankings, competitions) and CMAS championship protocols and records.

Learning it

Never teach yourself. A first course takes two or three days: theory (physics, physiology, safety), a pool session (static, dynamic, rescue) and, where there is water, a couple of depth sessions to 10–20 m. After it you know how to breathe up, how to equalise, how to be a buddy — and you have a certificate that lets you train with a club and book deeper sessions elsewhere.

The next levels take you deeper (to 30–40 m and beyond), teach mouthfill equalisation, free fall, and how to train on your own schedule. Instructors, judges and safety divers are certified separately.

What happens in the body

The urge to breathe comes from carbon dioxide building up, not from running out of oxygen. That is why it can be trained, and why it is not the same as danger.
The mammalian dive reflex — face in cool water, the heart slows, blood moves from the limbs to the core, the spleen releases stored red cells. Everyone has it; freedivers learn to trigger it faster.
Pressure doubles at 10 m. Lungs shrink, the ears and mask have to be equalised, and past 30–40 m the lungs are smaller than they can be on land — the “blood shift” keeps them from being damaged.
Contractions of the diaphragm start partway through a hold. They are uncomfortable, harmless, and a normal part of every long dive.

Safety

Never alone. Every dive and every pool hold needs a trained buddy watching, close enough to touch. Most freediving deaths happen to people alone in water — often in a pool or a bathtub.
No hyperventilation. Fast deep breathing before a dive removes the CO₂ warning and does nothing for oxygen; it is how blackouts happen.
One up, one down. In depth training the buddy meets you in the last 10 m, where blackouts occur, and watches you for 30 seconds after you surface.
Blackout and LMC (loss of motor control) are the two things a buddy is there for: hold the airway above the water, remove the mask, tell the diver to breathe — “blow, tap, talk”. A properly rescued blackout has no lasting effect; an unwatched one is fatal.
Equalise early, never force it. Ear and sinus injuries are the most common ones in the sport and nearly all of them are avoidable.
Rest between dives — at least twice the dive time in depth, and be honest about how you feel on the day.

How a competition works

The day before, every athlete announces a performance (a time, a distance or a depth). On the day, you get an official top (OT) — the minute your dive must start in. A countdown leads to it, with the final ten seconds counted aloud (the Countdown on this site does exactly that).

After surfacing you have 15 seconds for the surface protocol: remove facial equipment, give the OK sign, say “I'm OK” — in that order, to the judge, without going under. The judges then show a card:

White — a clean dive; it counts, and beats the announcement if you went further.
Yellow — a penalty: a short announcement, a grab of the rope, a late start, an early turn. The result counts with points taken off.
Red — disqualification: a blackout, loss of motor control, a failed protocol, an unfinished dive.

Points are given per discipline (for example, one point per metre in dynamic, one per second in static, one per metre of depth), and rankings across a competition or a season add them up. The full picture — both federations, side by side — is on the Competition rules page. Results published by the federation are the ones that appear on your profile as official; anything you keep here yourself is shown once a witness confirms it.

Glossary

Apnea: Not breathing; the sport's other name.
PB: Personal best — your best result in a discipline.
NR / CR / WR: National, continental, world record.
OT: Official top: the start time of a competition dive.
AP / RP: Announced performance / realised performance.
Breathe-up: The calm breathing before a dive.
Packing: Taking extra air into the lungs after a full breath, with the mouth — an advanced and debated technique.
Frenzel / mouthfill: The two main ways of equalising the ears at depth; mouthfill is what takes you past 30–40 m.
Free fall: The part of a deep dive where you stop swimming and sink.
Blackout (BO): Losing consciousness from low oxygen, usually near the surface.
LMC / samba: Loss of motor control after surfacing — shaking, unfocused, but conscious.
Lanyard: The tether between the diver's wrist or waist and the competition line.
Monofin / bi-fins: One large fin for both feet, or two separate ones.
Neutral athlete: Someone competing under the federation's flag rather than a country's.

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