PADI vs SSI vs SDI – Which agency should you choose for scuba certifications in 2026

TL;DR? It doesn’t really matter that much — pick the instructor, not the agency.

But you’re probably here because you want to learn a bit more than that, right? Fair enough. First, let’s talk about what certification agencies actually sell, and then we’ll go through each one and discuss the pros and cons.

What do certification agencies actually sell

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Courses, right? Well… that’s partially accurate. Agencies sell course materials and issue certifications. At a very basic level, they’re not that different from say… IT certification agencies. Sure, besides the materials themselves, most also offer e-learning platforms and various other add-ons. But what’s important to understand is that agencies are not the ones actually teaching your course, and instructors do not work for the agencies. They are, rather, their custoemrs — because an instructor (after going through the certification process) can teach courses for any agency.

Why there aren’t big differences between agencies

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The first question I usually get when potential customers realize I don’t teach PADI courses is: “So the certification isn’t as widely recognized, right?” It absolutely is 🙂

All major certification agencies are part of two international organizations within which they standardize courses and mutually recognize certifications. These are RSTC and EUF (European). All the agencies mentioned above — plus another hundred or so we’ve never heard of — are members and globally recognized.

What does all this theory mean for you? It’s simple:

• The minimum standards (the course syllabus, let’s say) are so similar that you won’t notice any major differences
• Certifications issued by any of them enjoy the same international recognition. In practice, you can dive anywhere in the world with any of them

So what are the differences?

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The criteria I look at, as an instructor, when choosing which agency to work with are:

Quality of materials and e-learning

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You wouldn’t like it if I handed you a 500-page PDF to read before the course, right? Me neither. Most major agencies offer e-learning in 2026. Not all of them though. And even here, the quality of the materials differs — without getting into instructional design details, the better the materials, the easier it is for you to understand the theory and apply it.

Openness to change

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You’ve probably already realized that scuba diving has a certain… let’s call it a healthy resistance to change. And I say healthy because this isn’t a risk-free sport, and you want to make sure that any change you implement increases safety, not the other way around. But you have to draw the line someplace. Take dive computers as an example — did you know there are agencies that, until just a few years ago, didn’t include computer use in their mandatory materials? Bit ridiculous, right?

Online services and customer service

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You’re starting to see a pattern, right? Let’s say you lose your certification card — how would you feel if you had to send a written request (yes, by mail) and wait about a month to receive a replacement? Yes, this still happens in 2026. Same goes for customer service — you want to know that, when needed, you can pick up the phone and reach someone who can actually help you.

An honest comparison between the three largest agencies available in Romania

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PADI

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Pff, here we go. Okay — PADI is the largest agency in terms of number of instructors, dive centers, and certified divers. How large exactly? We don’t really know, because they don’t publish those numbers. As a result, they also have the most recognizable brand. Does that mean anything for divers? Not really, but brand recognition leads many beginners to only look for PADI instructors and dive centers, simply because it’s the only agency they’ve heard of. Think Xerox. I think for a long time they even tried to promote the phrase “get your PADI” as a replacement for dive cert.

PADI materials are okay; openness to change… let’s call it so-so 😄. There is (at least among more advanced divers) a perception that PADI tries very hard to sell as many courses as possible, leaving quality on a secondary level (hence the acronym “Put Another Dollar In”). My view is that PADI is a business, like all the others, and wants to make money — the people who actually create the reputation are the dive centers and instructors.

A few things I don’t particularly like about PADI:

• their standards are not publicly available for potential clients → I send the course standard we’re discussing in the very first email to a potential student
• in recent years they’ve adopted an aggressive policy toward other agencies → for example, if you want to teach PADI courses, you must teach only PADI
• technical courses have outdated materials and a structure that doesn’t make much sense to me
• the brand costs money — both materials and certifications are significantly more expensive than all other agencies, without clear benefits beyond the brand itself

SSI

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SSI has grown a lot in recent years. Again, we don’t know exactly how much, for the same reasons. It’s clear they invest heavily in branding, and it shows. The quality of the materials is good, you can do almost everything online, and they have a very active community. So they tick most of the criteria above. HEAD Group (the sports equipment manufacturer) owns SSI and, among other things, also owns Mares (a fairly large dive equipment manufacturer), so if you’re wondering why you tend to see those brands together that’s why.

Why we decided not to work with SSI:

• first of all, SSI doesn’t have the concept of an independent instructor (i.e., not affiliated with a physical dive center). Given our principles, we don’t really want a brick-and-mortar location at this time.
• almost as important, SSI technical courses are still relatively early-stage.

SDI (and TDI)

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You’re probably wondering by now: okay, so who do you work with? We finallyu got there 😄 — at the moment, we work with SDI (Scuba Diving International) and TDI (Technical Diving International), both brands of International Training. TDI is one of the agencies that laid the foundations of technical diving, with its founders splitting off from IANTD in 1993. SDI appeared a bit later, using the technical diving foundations of TDI, but oriented towards recreational divers.

For us, SDI/TDI tick all the boxes — the materials are very good and available online in an easy-to-use format, and customer service is excellent. SDI was the first agency to adopt dive computers in their courses, moving away from teaching decompression tables — or rather, removing the obligation to teach them.

The technical diving “pedigree” that comes with TDI is also important for us. Our courses include what we consider the fundamentals of diving (buoyancy, trim, and propulsion) starting from Open Water, but we also want to be able to offer high-quality technical diving courses, and TDI has by far the best technical materials of the three.

Conclusion

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If it wasn’t clear by now, our recommendation is to choose an instructor you actually like and relate with. It doesn’t really matter whether they work with PADI, SSI, SDI, or any other recognized agency — what matters much more is that they:

• respect the standards of the chosen agency (unfortunately, not everyone does)
• do everything they can to ensure a safe learning environment, both physically and psychologically
• prepare you for real-world diving, not just to tick boxes during the course

We believe we check all the boxes above — and go much, much further. So if you want to learn more about us, read on about our philosophy, the instructor, and the courses we offer — where we explain why we’re different in each of these areas.