SDI, PADI, SSI & More – Which Scuba Agency Is Right for You?

One of the most common questions we get at the dive shop is:“What’s the difference between SDI, PADI, SSI, NAUI…? Does it really matter?”

The short answer? All of them will teach you to dive safely and get you certified. But each agency has its own style, teaching approach, and structure, and will grant you an international diving license that is recognized by all other diving agencies. It also means that you have full mobility between all agencies (to instructor level), and can continue your education via the agency of your choice.

However, once you go pro, those differences can start to shape your path... So let’s break it down in a simple, no-nonsense way.

Same Ocean, Different Roads

First things first: all major scuba training agencies follow international standards (like ISO or WRSTC). That means an Open Water Diver certification from any of them - SDI, PADI, SSI, etc. - is valid worldwide. You’ll be able to rent gear, join fun dives, and take more courses no matter who certified you.

The real difference lies in how the material is taught, how flexible the training is, and what kind of philosophy the agency follows. Especially once you start looking at Divemaster and Instructor levels, the agency you choose can shape your experience and job options.

PADI – The Global Giant

PADI is the biggest and most recognized scuba agency in the world. You’ll see the logo everywhere, especially in high-volume tourist spots like the Caribbean, parts of Thailand, and Central America. Their system is very standardized, so whether you're in Bali or Mexico, the course will be taught pretty much the same way.

It’s consistent, and many dive centers love the name recognition. But for some instructors and dive pros, it can feel a bit rigid. There’s less room for tailoring courses or adapting to real-world dive shop needs.

Moreover, PADI courses are usually more expensive due to the higher costs of certifications, learning materials, and annual fees, which dive centers and diving professionals have no choice but to add these surcharges to the price of their services.

SDI – A More Modern Approach

SDI (Scuba Diving International) is built on the idea that diving should be flexible, practical, and grounded in real experience. It’s the recreational side of TDI—one of the most respected technical diving agencies in the world—and that shows in the way SDI trains both students and professionals.

What we like about SDI (and why we use it here at SK Academy) is that it lets instructors teach with freedom and responsibility. The academics are all digital (though manuals can be used, and sometimes preferred), and instructors are encouraged to adapt their teaching style to the actual needs of their students. It’s especially good for people who learn better hands-on and want a deeper understanding, not just box-checking.

SDI is growing fast in places like the Philippines, North America, East Asia, and Europe, and is well accepted in the professional world.

SSI – App-Based & Streamlined

SSI (Scuba Schools International) has become very popular, especially in Europe and parts of Asia (especially in Thailand, where it became an industry leader). Their platform is slick and app-driven—your e-learning, logbook, and certification card are all in one place.

SSI instructors must work through SSI-affiliated shops, so there’s less flexibility for independent instructors, but the system works well for many divers and centers that want a tight structure. It’s clean and efficient—great if you love learning by app.

NAUI – More Freedom, More Academic

NAUI is the oldest US-based training agency and is still well respected in the U.S., the Middle East, and among some technical divers. The NAUI approach gives instructors more academic freedom, which can lead to very strong training, but it also means the course experience can vary a lot depending on the instructor.

You’ll mostly find NAUI centers in the U.S. or specialized locations elsewhere, and it’s less common in mainstream tourist areas.

CMAS – Traditional & Club-Based

CMAS is a French agency, often linked with national federations. You’ll find it strong in countries like France, Germany, and Italy, and in parts of South America.

CMAS courses tend to be more thorough and time-intensive, and they’re often delivered through diving clubs. This works great for those who like a slower, more community-based learning style, but it’s not the go-to agency in most tropical resort destinations.

Also, their diving licenses are more liberal in terms of what the diver can do underwater, due to the long and meticulous training. However, this divergence from the usual diving standards also exposes the divers to more unnecessary risk.

Going Pro? Here's Where It Matters.

If you're staying recreational, you can pretty much pick any agency you feel comfortable with. But once you’re thinking about going Instructor, your choice starts to matter more.

Some dive destinations are dominated by a specific agency. For example:

• Indonesia, Central America: mostly PADI

• Europe: SSI, SDI, CMAS, and PADI, depending on the country

• Philippines: SDI, SSI, and PADI are all strong

• North America: SDI, PADI, and NAUI are all present

SDI instructors have the benefit of teaching with a bit more flexibility and practical depth, and their certifications are recognized worldwide. PADI instructors might have an easier time finding work in heavily PADI-driven markets. SSI instructors usually work within a specific shop.

Crossing Over from One Agency to the Other

Crossing over is possible - you can crossover from one agency to another with some extra training and a crossover course for instructors. There are a few restrictions, though: PADI doesn't allow instructors to crossover to their organization, thus encouraging soon-to-be instructors to choose PADI first if they want to crossover to another agency later (as many instructors work in several agencies simultaneously).

Other agencies offer more flexibility, and you can find the latest details on their official websites. Since all instructors follow the same global training standards set by the WRSTC, the differences mostly come down to teaching style, course structure, and how lessons are planned and delivered.

Final Thoughts: It's Not About the Logo—It's About the Learning

No matter which agency you choose, the most important thing is who’s teaching you. A great instructor will make the course meaningful, safe, and fun, whether their shirt says PADI, SDI, or something else.

That said, if you're looking for a modern, flexible, and experience-driven approach to scuba education, we believe SDI offers something special, especially if you're thinking of going pro. SDI expects its instructors to be adaptable, professional, and focused on real-world teaching. Rather than rigidly following scripts, SDI instructors are trusted to tailor their approach to the needs of each student while still meeting global training standards. The agency emphasizes practical experience, clear communication, and modern, digital-first education. Instructors are encouraged to create confident, capable divers—not just certified ones—by blending solid skills, flexibility, and ethical, experience-based instruction.

Come visit us at SK Academy, a renowned Panglao diving center and let’s find the path that fits you best. We’re here to help you grow—from your first breath underwater to your first class as a dive instructor.