PADI vs SSI vs NAUI: How the Scuba Training Agencies Compare

The short answer

For a recreational diver, PADI, SSI and NAUI certifications are all accepted by dive operators around the world. Their beginner courses teach the same core skills to the same depth limits, because the major agencies follow shared international minimum standards for diver training. You can train with one agency and take your next course with another.

So the better question is not "which agency?" but "which school and which instructor?" Our guide to choosing a dive school covers that in detail. Still, the agencies do differ in how they organize training, and it helps to know how.

PADI

The Professional Association of Diving Instructors is the largest training agency in the world, with dive centers in almost every diving destination. Its course structure is very standardized: the same course runs the same way wherever you take it. Course materials, including the online theory (eLearning), are usually bought as part of the course, and your certification is available as a digital card in the PADI app.

Strengths: available almost everywhere, consistent course structure, a huge range of specialty courses.

SSI

Scuba Schools International trains through affiliated dive centers. SSI instructors work through a dive center rather than independently, and the dive center is responsible for the quality of training. Digital learning materials are accessed through the MySSI app, and many centers include them in the course price. SSI gives instructors some flexibility in the order skills are taught, within its standards.

Strengths: strong dive center network, well-regarded digital materials, flexible teaching sequence.

NAUI

The National Association of Underwater Instructors is a non-profit association and one of the oldest agencies. It is especially common in the United States, including in universities and public safety diving. NAUI's motto, "Dive Safety Through Education," reflects its emphasis on instructors' freedom to go beyond the minimum, and its courses often include more content than required.

Strengths: non-profit, instructor flexibility, strong presence in North American training programs.

Side-by-side comparison

	PADI	SSI	NAUI
Beginner course	Open Water Diver	Open Water Diver	Scuba Diver
Second course	Advanced Open Water Diver	Advanced Adventurer	Advanced Scuba Diver
Rescue level	Rescue Diver	Stress & Rescue	Rescue Scuba Diver
First pro level	Divemaster	Dive Guide / Divemaster	Divemaster
Organization	Company	Company	Non-profit association
Where it is common	Worldwide	Worldwide, strong in Europe and Asia	Strongest in North America

Course names and structures change from time to time; check the agency's current course list before you book.

Other agencies

PADI, SSI and NAUI are not the only options. Other well-known agencies include RAID, SDI (with its technical arm, TDI), BSAC in the United Kingdom and CMAS, an international federation with member organizations in many countries. Certifications from these agencies are also widely recognized. BSAC and many CMAS federations train through clubs rather than commercial dive centers, which can be a sociable, lower-cost way to learn if you live near one.

Switching agencies later

Switching is easy. Dive centers accept certifications from other recognized agencies as prerequisites, so an SSI Open Water Diver can take a PADI Advanced Open Water course, and vice versa. Some agencies also offer a "crossover" to issue their own equivalent card, which can matter if you later train as a professional with that agency.

How to choose

List the dive schools you could realistically train with, at home or where you are travelling.
Compare the schools, their instructors and what is included, using our guide to scuba certification cost.
Choose the best school. Accept whichever agency it teaches.

If you are new to all of this, start with our overview of scuba certification levels; the ladder is the same whichever agency you pick.