On one breath,
into the sea
One breath, all the way down.
Freediving means descending, surfacing, and breathing again on a single inhaled breath (breath-hold, apnea), with no breathing equipment. It is fundamentally different from scuba, where you breathe continuously underwater from a tank and regulator. And Korea has a living, world-recognized breath-hold diving culture: the haenyeo (women free-divers) of Jeju.
Hold your breath: freediving. Bring a tank: scuba.
Freediving relies on breath-hold (apnea) to descend, then you surface and breathe again. The two aren't mutually exclusive, so many divers learn both.
- Breathing: one breath vs. continuous / Gear: lightweight (mask, fins, weights, suit) vs. heavy equipment
- Bottom time: tens of seconds to a few minutes vs. 30 minutes to 1 hour+ / Bubbles: none (easier to approach marine life) vs. exhaled bubbles
- Decompression: usually none vs. nitrogen absorption and pre-flight surface interval / Equalization: Frenzel preferred vs. Valsalva common
Six depth, four pool
Competitive freediving is split into depth and pool disciplines, with AIDA and CMAS governing competitions and world records.
CWT (constant weight, standard) · CWTB (bifins) · CNF (no fins, hardest) · FIM (free immersion, pull the rope) · VWT (variable weight sled) · NLT (no limits, most dangerous).
STA (static, the only timed discipline) · DYN (dynamic with fins) · DYNB (bifins) · DNF (no fins).
A separate system from scuba C-cards
Leading agencies include AIDA (founded 1992), CMAS, Molchanovs, PADI Freediver, and SSI Freediving. Progression runs from entry to beginner/intermediate to advanced to instructor, with levels usually divided by STA, DYN, and CWT benchmarks. Depth and time figures are as of 2025–2026 and vary by agency and year.
- Beginner (first open water): AIDA 2 — CWT 16m · STA 2:00 · DYN 40m / PADI Freediver ~10m / SSI Level 1 ~20m
- Advanced: AIDA 4 — CWT 32m · STA 3:30 · DYN 70m / SSI Level 3 ~40m / Molchanovs Wave 3 34–40m
The main risk is hypoxic blackout
The main risk in freediving is hypoxic blackout (loss of consciousness). Near the end of a breath-hold or during ascent, low oxygen to the brain can make you pass out. The absolute rule is ‘never dive alone’ — always dive with a directly supervising buddy, one at a time (one up, one down).
- AIDA 1 is a pool/confined-water introduction (depth not applicable); AIDA 2 is usually the first open-water certification.
- Molchanovs Wave 2 figures are unconfirmed — don't state them as fact. Depth and time vary by agency and year.