Freediving Disciplines

A Complete Guide to Every Competitive Category

Freediving is not one single sport.

It is a collection of disciplines — each testing a different aspect of human ability.

Some disciplines measure depth.
Others measure time.
Others measure distance.

Some reward power.
Others reward efficiency.

All reward composure.

Understanding the disciplines is essential to understanding competitive freediving.

What Is a Freediving Discipline?

A discipline is a specific competitive category with defined rules.

Each discipline determines:

  • How the diver moves

  • What equipment is allowed

  • Whether the dive is vertical or horizontal

  • What performance is measured

Modern competitive freediving is governed internationally by organizations such as:

Each federation defines discipline standards, safety requirements, and record validation.

Two Main Categories

Freediving disciplines fall into two broad groups:

  1. Depth Disciplines (Open Water)

  2. Pool Disciplines

They test different systems.

Depth Disciplines

Depth disciplines involve descending vertically along a line in open water.

The diver announces a target depth before the dive.

Performance is measured by:

  • Depth reached

  • Proper surface protocol

  • Safety compliance

Pressure increases rapidly with depth.

These disciplines require equalization and pressure adaptation.

1. Constant Weight (CWT)

Constant Weight is the most recognized depth discipline.

The diver:

  • Descends and ascends using fins

  • Cannot pull on the line

  • Cannot change weight during the dive

CWT demands:

  • Efficient fin technique

  • Calm descent

  • Controlled ascent pacing

2. Constant Weight Bi-Fins (CWTB)

CWTB follows the same rules as CWT — but requires bi-fins instead of a monofin.

Bi-fins:

  • Require alternating leg movement

  • Emphasize symmetry and efficiency

  • Often feel more natural to beginners

3. Free Immersion (FIM)

In Free Immersion, the diver:

  • Pulls down and up the line using arm strength

  • Uses no fins

  • Must remain in constant contact with the rope

FIM is often taught early because:

  • It allows slower, controlled descent

  • Equalization timing is easier to manage

  • Movement is deliberate and rhythmic

4. Constant Weight No Fins (CNF)

CNF is considered by many to be the most physically demanding discipline.

The diver:

  • Uses no fins

  • Does not pull on the rope

  • Relies entirely on swimming power

Efficiency becomes critical.

Small technical errors cost oxygen quickly.

CNF is respected for its purity.

Pool Disciplines

Pool disciplines remove pressure from the equation.

There is no depth compression.

Instead, performance is determined by oxygen management and efficiency.

1. Static Apnea (STA)

Static apnea measures:

  • The longest breath-hold duration

The diver floats face-down in a pool, supported by a safety diver.

This discipline tests:

  • Mental control

  • CO₂ tolerance

  • Relaxation

Contractions are intense.

Stillness is essential.

2. Dynamic Apnea (DYN)

Dynamic apnea measures:

  • Horizontal distance underwater

DYN typically uses a monofin.

The diver swims underwater in a pool for maximum distance.

Streamlining and technique dominate.

3. Dynamic Bi-Fins (DYNB)

DYNB follows the same structure as DYN but uses bi-fins.

Movement differs significantly from monofin technique.

Efficiency and rhythm are key.

4. Dynamic No Fins (DNF)

Dynamic No Fins measures horizontal distance underwater in a pool without fins. The diver uses underwater breaststroke-style technique and streamlining to maximize efficiency.

DNF tests:

  • Technique efficiency (glide timing + stroke quality)

  • CO₂ tolerance and mental control

  • Oxygen economy under sustained effort

It’s often considered the “pool version” of CNF in terms of purity and physical demand — no fin propulsion, no shortcuts, just efficient movement.

How Disciplines Differ Physiologically

Depth disciplines stress:

  • Pressure adaptation

  • Equalization skill

  • Lung compression

  • Ascent oxygen management

Pool disciplines stress:

  • Oxygen efficiency

  • CO₂ tolerance

  • Streamlining

For the science behind these differences:
CO₂ vs O₂ in Freediving
Boyle’s Law in Freediving
Mammalian Dive Reflex Explained

Which Discipline Is Best for Beginners?

Many beginners start with:

  • Static apnea (STA)

  • Free Immersion (FIM)

These allow controlled skill development.

Constant Weight often becomes the long-term focus.

Some athletes specialize.

Others compete across multiple disciplines.

How Records Are Set

In competition:

  • Divers announce a target

  • Judges verify performance

  • Surface protocol confirms consciousness

  • Safety teams monitor every dive

Record recognition is governed by federations like AIDA International and CMAS.

White cards indicate valid dives.

Yellow cards indicate the diver did not meet the announced depth, time (static) or length (pool).

Red cards indicate rule violations or safety failures.

Records are not casual achievements.

They are formally ratified.

The Philosophy of Discipline

Each discipline teaches something different.

Depth disciplines teach surrender.

Static teaches patience.

CNF teaches efficiency.

FIM teaches control.

Dynamic teaches rhythm.

The discipline you choose often reflects your personality.

But all of them train peace in pressure.

Explore Each Discipline in Detail

→ Constant Weight (CWT) Explained

→ Constant Weight Bi-Fins (CWTB) Explained

→ Free Immersion (FIM) Explained

→ Constant Weight No Fins (CNF) Explained

→ Static Apnea (STA) Explained

→ Dynamic Apnea (DYN) Explained

→ Dynamic Bi-Fins (DYNB) Explained

→ Dynamic Np Fins (DNF) Explained

→ View Current World Records