Scuba Diving Certification Levels
A complete guide — from Open Water to Instructor
Qualified Divers Only
You must hold a valid, recognised scuba diving certification to attempt any scuba diving activity. This article is a refresher resource only — it does not replace professional training, certification, or the guidance of a qualified dive instructor. Attempting to scuba dive without proper certification is extremely dangerous. VisPro accepts no legal responsibility for accidents, injuries, or loss sustained by unqualified or qualified divers as a result of this content.
Wondering how the different types of scuba diving certifications fit together? Recreational diving follows a clear progression of dive certification levels, from your very first course through to professional ratings. Below is a plain-English breakdown of the scuba diving certification levels and what each one lets you do.
What Are the Different Scuba Diving Certification Levels?
Open Water Diver
Up to 18 mThe entry-level scuba certification and the starting point for most divers. You learn to assemble and use your gear, manage buoyancy, clear your mask, and dive safely with a buddy. Once certified you can dive independently (with a buddy) to 18 metres anywhere in the world.
Advanced Open Water Diver
Up to 30 mBuilds on Open Water with a set of adventure dives — typically deep and underwater navigation plus electives such as night, wreck, or drift diving. It extends your depth limit to 30 metres and gives you supervised experience across different dive types.
Rescue Diver
Up to 30–40 mA demanding but rewarding course focused on preventing and managing diving emergencies — self-rescue, recognising and helping stressed divers, and search-and-recovery. Rescue Diver is widely regarded as the level where divers become far more capable and confident.
Divemaster
Professional levelThe first professional rating. Divemasters supervise dive activities, assist instructors, guide certified divers, and demonstrate a high standard of dive skills and knowledge. This is the gateway to working in the dive industry.
Instructor
Professional levelThe highest common recreational rating. Certified instructors can teach and certify new divers across the certification levels. Reaching Instructor requires professional-level experience, an instructor development course, and passing an instructor examination.
PADI vs NAUI vs SSI vs TDI — which agency?
The certification levels above are broadly the same across every major training agency — the names and exact depth limits differ a little, but all are recognised worldwide. Pick the agency your local dive shop teaches, or cross-train across several to broaden your skills.
PADI
The largest and most widely recognised agency worldwide — you'll find PADI dive shops almost everywhere.
SSI
Scuba Schools International — a modern, digital-first approach with flexible, modular training.
NAUI
Known for more flexible, instructor-led training and a strong focus on dive theory.
TDI
Technical Diving International — the go-to for technical and enriched-air (nitrox) certifications.
Scuba certification levels — frequently asked questions
What are the levels of scuba diving certification?
The main recreational scuba diving certification levels, in order, are Open Water Diver, Advanced Open Water Diver, Rescue Diver, Divemaster, and Instructor. Open Water is the entry level (to 18 m), Advanced Open Water extends your depth to 30 m, Rescue Diver teaches emergency management, and Divemaster and Instructor are professional ratings.
What is the difference between Open Water and Advanced Open Water?
Open Water Diver is the foundational certification that lets you dive to 18 metres with a buddy. Advanced Open Water builds on it with adventure dives (usually including deep and navigation) and extends your depth limit to 30 metres. You do not need to be an expert to take Advanced Open Water — it is designed to give newer divers supervised experience across different dive types.
How long does it take to get a scuba diving certification in Australia?
An Open Water course in Australia typically takes 3 to 4 days, combining theory, confined-water skills, and four open-water training dives. Advanced Open Water usually takes a further 2 days. Timeframes vary by dive school, weather, and whether you complete the theory online (eLearning) beforehand.
What scuba certification do I need to dive the Great Barrier Reef?
An Open Water Diver certification is enough to dive most of the Great Barrier Reef, as many popular sites sit within recreational depths. For deeper reef and wall sites an Advanced Open Water certification is recommended. Snorkellers need no certification, and most operators also offer supervised introductory dives for uncertified divers.
What is the highest level of scuba diving certification?
Within recreational diving, Instructor is the highest common certification level — instructors can teach and certify new divers. Beyond that sit specialty and technical ratings (such as Master Scuba Diver, technical/trimix certifications, and instructor-trainer roles) for divers who want to go deeper or teach at higher levels.