Certifications
Courses, minus the sales pitch
Concept-level course pages that name the equivalent PADI, SSI, NAUI and RAID versions, because the diving is the same, whatever the card says. Plus neutral profiles of the agencies themselves.
- Start here
- Freediver (Entry Level) · Open Water Diver · Try Dive (Discover Scuba)
- Next steps
- Advanced Open Water · Rescue Diver
- Going pro
- Dive Instructor · Divemaster
The course ladder
| Course | Level | Min age | Depth limit | Typical time |
|---|---|---|---|---|
| Freediver (Entry Level) Structured breath-hold training: physiology, relaxation, and safety protocols across pool… | Entry | 15 | 16 m | 2-3 |
| Open Water Diver The world's entry-level scuba certification: theory, confined-water training, and four… | Entry | 10 | 18 m | 3-5 |
| Try Dive (Discover Scuba) A supervised first breath underwater with no certification required: a short briefing… | Entry | 10 | 12 m | half-day |
| Advanced Open Water The second rung of the recreational ladder: a set of instructor-led adventure dives… | Advanced | 12 | 30 m | 2-3 |
| Rescue Diver The course that shifts your attention from yourself to the whole dive: stress… | Advanced | 12 | — | 3-4 |
| Deep Diver Specialty Structured training for the 18-40 m band: gas planning, narcosis awareness, and… | Specialty | 15 | 40 m | 2 |
| Drift Diver Specialty Technique for diving in current: negative entries, group cohesion, surface-marker… | Specialty | 12 | — | 1 |
| Dry Suit Diver Specialty Training to dive warm and dry in cold water: managing a second buoyancy volume, seals and… | Specialty | 10 | — | 1-2 |
| Emergency Oxygen Provider A half-day, no-prerequisite course on recognizing dive injuries and delivering emergency… | Specialty | — | — | 0.5 |
| Enriched Air Nitrox The most popular specialty in diving: a short, mostly classroom course on breathing… | Specialty | 12 | — | 0.5-1 |
| Night Diver Specialty Two to three guided dives after dark: light handling and signals, close navigation, and… | Specialty | 12 | — | 1-2 |
| Peak Performance Buoyancy A short course devoted entirely to the skill that defines good divers: precise weighting… | Specialty | 10 | — | 1 |
| Sidemount Diver Learn to carry cylinders at your sides instead of on your back: a cave-born configuration… | Specialty | 15 | — | 2 |
| Underwater Navigator Compass work, natural navigation, and distance estimation across three dedicated dives -… | Specialty | 10 | — | 1-2 |
| Wreck Diver Specialty Training for diving sunken ships and aircraft: hazard assessment, line and reel work, and… | Specialty | 15 | 30 m | 2 |
| Dive Instructor Instructor development and examination: the training that qualifies you to certify new… | Pro | 18 | — | 10-14 plus a 2-day examination |
| Divemaster The first professional rating: leadership training that qualifies you to guide certified… | Pro | 18 | — | 2-8 weeks |
| Cavern & Cave Diving The staged path into overhead environments: cavern training within the daylight zone… | Technical | 18 | 21 m | 2-3 for cavern; a week or more for full cave |
| Intro to Rebreathers Unit-specific training on closed-circuit rebreathers: how the loop, scrubber, and oxygen… | Technical | 18 | — | 3-5 |
| Intro to Technical Diving The doorway out of recreational limits: redundant equipment, disciplined gas planning… | Technical | 18 | 40 m | 3-5 |
Depth limits shown are the mainstream training conventions, not laws, and they exist because the physics does not negotiate.
The agencies
BSAC (British Sub-Aqua Club)
The United Kingdom's national governing body for scuba, founded in 1953 and built on volunteer-taught club branches…
CMAS (World Underwater Federation)
The world federation of national diving federations, founded in 1959 with Jacques-Yves Cousteau as its first president…
GUE (Global Underwater Explorers)
A nonprofit training organization founded in 1998 from Florida cave-exploration roots, known for standardized equipment…
IANTD (International Association of Nitrox and Technical Divers)
Founded in 1985 to teach the then-heretical nitrox, IANTD became one of the pioneers of formal technical training…
NAUI (National Association of Underwater Instructors)
One of the oldest recreational training agencies, founded in 1960 in the United States, with a not-for-profit heritage…
PADI (Professional Association of Diving Instructors)
The world's largest recreational dive training organization, founded in 1966, with a standardized modular system taught…
RAID (Rebreather Association of International Divers)
The youngest major agency, founded in 2007 around rebreather training and now a full-spectrum system, known for fully…
SSI (Scuba Schools International)
A global training agency founded in 1970, known for free digital learning materials, a dive-center-based teaching…
TDI / SDI (Technical Diving International / Scuba Diving International)
Sister agencies under the International Training family: TDI, founded 1994, is one of the world's leading…