Freediving Certification and Agency Guide
Compare the stages, depth and static requirements, and training focus of AIDA, SSI, PADI, and CMAS freediving courses.
How to use this guide
A freediving certification records that you completed a training agency's theory, in-water training, and assessments. Before choosing a logo, check where and from whom you will learn, whether your goal is pool or open-water freediving, and how much safety and rescue practice the course includes.
The courses below are placed side by side by learning purpose. They are not declared to be exact equivalents. Similar-looking stages can have different prerequisites, training depths, performance assessments, session counts, and certification limits.
The depth and breath-hold numbers in the tables are not targets for solo practice. Training still requires a trained buddy, instructor supervision, and gradual adaptation. Junior standards, medical requirements, national federation rules, and center procedures can differ, so confirm the latest official requirements before enrolling.
Already considering a professional path?
Instructor and instructor-trainer programs have different prerequisites from recreational freediving courses.
Major course pathways at a glance
Use this table to find courses with a similar learning purpose. It does not promise automatic recognition or one-to-one equivalence between agencies.
| Learning stage | AIDA | SSI | PADI | CMAS |
|---|---|---|---|---|
| Shallow-water introduction | AIDA1 | Basic Freediver | Basic Freediver | Discovery Apnea Diver |
| First open-water certification | AIDA2 Freediver | Freediver | Freediver | 1★ Apnea Diver |
| Advanced skills and safety | AIDA3 Advanced Freediver | Advanced Freediver | Advanced Freediver | 2★ Apnea Diver |
| Deep and performance training | AIDA4 Master Freediver | Performance Freediver | Master Freediver | 3★ Apnea Diver |
Before comparing depth and static numbers
- STA (Static Apnea): A breath-hold performed without moving at the surface.
- DYNB (Dynamic with Bifins): The horizontal distance covered underwater using bifins.
- CWT or CWTB (Constant Weight): A vertical descent and ascent without changing ballast; CWTB specifies bifins.
- Maximum training depth: The deepest point at which an instructor may conduct that course. It is not always the depth a student must reach to qualify.
The published figures also mean different things. The AIDA and CMAS rows show published certification performance requirements, the PADI rows show course ranges and performance goals, and the SSI rows show maximum training depths published on its course pages. SSI's public course pages do not give one STA pass time to apply across every level, so this guide does not invent one.
Key standards and training focus by course
This is a summary of representative published adult standards. It omits detailed skill assessments, junior standards, and regional exceptions.
| Agency and course | Depth reference | STA | Training focus and conditions |
|---|---|---|---|
| AIDA1 | Maximum training depth 10m | No performance requirement | A one-day introduction to relaxation, finning, duck dives, and equalization |
| AIDA2 | CWTB 12m / maximum training depth 20m | 2:00 | Breathing cycle, basic physiology, buddy safety, at least two confined- and three open-water sessions |
| AIDA3 | CWTB 24m / maximum training depth 30m | 2:45 | Frenzel, freefall, training tables, pressure changes, and blackout risk management |
| AIDA4 | CWTB 32m / maximum training depth 38m | 3:30 | Mouthfill, deep-diving physiology, warm-ups and supervision; First Aid and CPR within two years |
| SSI Basic Freediver | Maximum training depth 5m | No public numeric standard | Breath-hold comfort, basic movement, and buddy safety in pool or confined water |
| SSI Freediver | Maximum training depth 20m | No public numeric standard | A breathing session, at least two confined- and two open-water sessions, equalization, and rescue skills |
| SSI Advanced Freediver | Maximum training depth 30m | No public numeric standard | Freediver plus six logged sessions; Frenzel, freefall, session planning, and four open-water sessions |
| SSI Performance Freediver | Maximum training depth 40m | No public numeric standard | Advanced plus 30 logged sessions; deep equalization, performance and competition techniques, and five open-water sessions |
| SSI Master Freediver | No separate course depth | No separate course requirement | A recognition rating earned through specialties and logged sessions, not the next training course |
| PADI Basic Freediver | Confined-water maximum 6m | 1:30 | Knowledge and confined water, DYN 25m, and basic buddy and rescue skills; no open-water rating |
| PADI Freediver | Course range 10–16m / CWT goal 10m | 1:30 | Knowledge, confined water, at least two open-water sessions, FIM, CWT, and buddy procedures |
| PADI Advanced Freediver | Course range 16–24m / CWT goal 20m | 2:30¹ | Stretching and relaxation, deeper FIM and CWT, plus advanced buddy and rescue procedures |
| PADI Master Freediver | Course range 24–40m / CWT goal 32m | 3:30 | Fitness and wellness, mouthfill, warm-up and workup dives; CPR and First Aid within 24 months |
| CMAS Discovery | Dive to 2m | 1:00 | A confined-water introduction to breathing, finning, buoyancy, duck dives, and basic safety |
| CMAS 1★ Apnea Diver | CWT 10m | 1:30 | Basic physics, physiology, equalization, buddy safety, eight theory hours, and four practical sessions |
| CMAS 2★ Apnea Diver | CWT 20m | 2:30 | Relaxation, dive planning, tides and currents, blackout rescue, and first aid |
| CMAS 3★ Apnea Diver | CWT 30m | 3:30 | Advanced equalization, rescue and CPR, open-water leadership, and six practical sessions |
What to check about each agency
¹ The published PADI Advanced Freediver goal is 2:00 STA and 15m CWT for divers younger than 18.
AIDA
AIDA has a clear numbered path from AIDA1 to AIDA4 and publishes STA, DYNB, and CWTB performance requirements and minimum sessions. AIDA1 is an introductory experience without performance requirements; AIDA2 begins the fuller open-water skills and assessment path.
SSI
The training path can be read as Basic Freediver, Freediver, Advanced Freediver, and Performance Freediver. Specialty Freediver, Progressive Freediver, and Master Freediver are Recognition Ratings based on specialties and logged sessions, so do not compare them directly with another agency's Master course. SSI's public crossover chart also places PADI Freediver and Advanced in one band and marks CMAS as country-dependent.
SSI freediving courses · SSI Advanced Freediver
PADI
Basic Freediver is a confined-water rating, while Freediver adds open-water training. Advanced and Master expand relaxation, rescue, deep equalization, and training planning. Course depth ranges and performance goals are different concepts, so do not choose from an advertised maximum depth alone.
PADI freediving FAQ · PADI freediving education
CMAS
CMAS uses Discovery and 1★, 2★, and 3★ Apnea Diver levels, with increasing emphasis on rescue, first aid, and leadership. Cards may be administered through national federations, so confirm the local course name and applied standards with the relevant federation.
Checklist before enrolling
- Exact course name and card issued, and the instructor's current active status
- Prerequisite certifications, logs, swim assessment, minimum age, and medical screening
- Minimum theory, confined-water, and open-water sessions and the actual schedule
- Repeated hands-on practice in buddy supervision, surface recovery, LMC, and blackout rescue
- Site safety equipment and emergency plan, including line, buoy, lanyard, and emergency oxygen
- Extra practice, partial rating, or reassessment policy if a goal is not completed
- Crossover assessment required when entering with another agency's certification
Depth and STA are only part of the assessment. Prioritize enough instructor observation, feedback, and safety practice over the shortest schedule or deepest advertised target.
Frequently asked certification questions
Which agency has the best certification?
A logo cannot answer that on its own. Compare the instructor's teaching, safety culture, number of in-water sessions, training site, and the community you can practice with afterward.
Can I enter the next level with another agency's certification?
A crossover path may be available, but it is not automatic. Expect to show your card and logs and possibly complete an assessment of the previous level's knowledge and in-water skills.
Do I qualify as soon as I reach the STA time?
No. You must also complete knowledge, dynamic and depth skills, buddy supervision, surface protocol, and rescue assessments. Practice breath-holds only with a trained buddy and appropriate supervision.
Are SSI Master, AIDA4, and PADI Master the same course?
No. SSI Master Freediver is a recognition rating based on specialties and logged sessions. AIDA4 and PADI Master Freediver are separate training and assessment courses.
Must I dive to the table's depth before joining recreational dives?
A certification range and a sensible depth for today's dive are not the same. Plan conservatively around your condition, recent experience, environment, buddy capability, and local procedures.
Discuss the right first course for you
Ask a center for the exact course name and session plan, then compare its safety training and practice environment.