When trying to understand the complex world of scuba diving organizations and their certifications levels, it can become confusing.
In this article, I will lay out clearly for you all the details in a fully comprehensive guide so you can:
- Get familiar with the different diving organizations out there
- Understand better your diving certification and what it means in terms of skills
- Have a good understanding of the certification equivalencies between organizations
The different Diving Organizations and their history
While there are dozens of diving organizations worldwide, most of them are under the umbrella of CMAS the (Confederation Mondiale des Activité Subaquatique), this includes most of the national federations of each country like France (FFESSM), Italy (FIAS) or the Underwater Society of America in the US.
The institution was formally created in 1959 by a gathering of national federations including the ones stated above and a few others, who elected the famous french diving pioneer and explorer Jacque-Yves Cousteau as their 1st president.
With more over 130 affiliated organizations in 94 countries across five continents and over 3 million active members, CMAS remains the main regulator for most underwater activities.
The Professional Association of Diving Instructor (PADI) was founded in 1966 by John Cronin and Ralph Erickson.
Their idea was to breakdown the traditional training programs offered by NAUI in smaller levels and modules to allow recreational scuba divers to learn gradually and attract more people to the world of scuba diving.
This new philosophy of learning was a real disruption to the way scuba diving was taught.
A true pedagogical war machine, PADI standardized all its courses with learning material translated in basically all languages and leaves very little space for improvisation from instructors. This ensures the uniformity of PADI diver’s skills around the world and allows the company to scale and maintain its reputation more easily.
Their method became a worldwide success with PADI now being by far the most represented organization globally with over 27 million certifications issued since its creation and 6 600 dive centres scattered across the globe.
In 1970, Robert Clarke created The Scuba School International as an alternative to NAUI and PADI.
Since then, they have created an impressive network across the globe with more than 2 800 authorised diver centres in 110 countries and 35 offices worldwide. They offer an extensive list of diving certifications matching the international standards set by ISO and the WRSTC.
Their teaching philosophy relies on what they call “Comfort Through Repetition”, which is a method focusing on repeating skills over and over until they become automatical. In addition to this practical aspect, SSI developed an extended learning environment composed of digital resources and applications allowing you to practice and learn with great flexibility.
They differentiate themselves from PADI by allowing greater flexibility to their instructor, who can adapt the courses’ content to the situation more freely. However, they only allow their instructor to work in SSI affiliated dive centres which can be a bit of a struggle if you decide to make scuba diving your career down the line.
The National Association of Underwater Instructors traces its history back to 1955 when Bev Morgan, Al Tilman & Conrad Limbaugh created the first Underwater Instructor Certification Course which laid the foundation to the first diving training agency led by civilians.
In 1960 the same group of people joined by a few other early pioneers of Scuba Diving introduced the National Association of Underwater Instructor to diving passionate with the first NAUI stamped instructor course in Houston with 72 candidates.
Since its creation, NAUI became a leading institution recognised worldwide for their teaching standards, which inspired many organizations including PADI whose founding member was a NAUI instructor.
One of their main characteristics is their focus on teaching rescue skills early on. With for example exercises on how to save an unconscious diver. They also require students to learn how to skin dive.
This added focus on rescue and safety made it the go-to choice for the US military which uses their training programs.
While NAUI has a far fewer dive centres affiliated across the world than the previous ones in our list, the quality training standards they offer make it easy to be recognised worldwide for both recreational and professional diving.
Scuba Diving International is the sister organization of TDI (Technical Diving International) and was created in 1998 to expand TDI’s activities from the purely Tech Diving world.
Coming from a background of pure tech and “serious” diving, SDI brings to the table a solid badass reputation. Their teaching methods are focused on training their students in using the latest tools & technology available. For instance, they require the use of dive computers even at the very first entry-level course while many other organisations will only require a basic understanding of it and leave the dive leader in charge of monitoring the parameter of the dive.
They are also famous for being the first to offer a specific course to learn how to dive alone (Solo Diver), breaking the first rule every recreational diver ever heard. This, of course, is reserved for experienced divers with more than a hundred logged dives.
Combined with TDI for the tech diving courses and ERDI for commercial diving, the group became in a relatively short period a reference and leader in the competitive world of scuba diving organisations, with 26 offices globally and a network of dive centers in more than 100 countries.
The British Sub Aqua Club was founded in 1953 but launched its first instructor training course in 1960 around the same time as NAUI and CMAS. Since then it became a reference worldwide for its standard of training built to fit the infamous British weather and more demanding diving conditions. It is the official national governing body for the practice of scuba diving in the UK and is even presided over by the Prince Willam himself.
From the entry-level, divers are taught a much more comprehensive training against cold temperature and low visibility, learning how to deal with the risks cold and challenging conditions can have before, during and after the dive.
Like CMAS and NAUI, BSAC is a non-profit organization which promotes an associative and non-commercial conception of scuba diving. This mindset attracts many UK based divers who prefer this club lifestyle and community mindset to the more customers/company relationships found at PADI or SSI.
For-Profit vs Non-Profit - A Different philosophy
When looking at the different diving organizations and their course catalogue, something jumps straight to mind.
Some like PADI or SSI offer a long list of speciality courses which, in some cases, are mandatory to pass on to the next level, while CMAS for example or NAUI offer a smaller number of courses.
Of course, both NAUI & SSI teach its divers about altitude diving’s specificities or how to master your buoyancy.
But then why did SSI decide to create separate courses to teach you these skills while NAUI simply includes it in your Advanced Open Water course?
A different diving philosophy & teaching methods
The first reasons bring us back to the philosophy introduced by PADI in the late ’60s.
Scuba Diving was then taught as a complex discipline involving a lot of theoretical knowledge, a deep understanding of physiology and the mechanics of both the human body and newly invented gear.
Diving was not easy to get into, definitely not enough to master during your yearly vacation week with the kids.
I remember my father explaining how many pools dives he did back in the days and how much theory he knew before even setting foot on a diving boat. And boom! First dive at 30m on a wreck in the open sea.
And that’s where PADI innovated. By decomposing the learning process into smaller modules and restricting recreational diving practice to a no-decompression depth and time, they were able to open scuba diving to the larger audience.
Suddenly, you were able to enjoy the splendour of the underwater world safely, with a few days of practice and basic knowledge of the theory. This new conception of diving, coupled with the explosion of tourism and long haul flights, allowed for the industry’s rapid growth.
More courses = More money
The second reason is, of course, profitability. Being a for-profit organization matches particularly well with the subdivisions of the learning material.
It makes perfect business sense to provide easy & safe access to scuba diving to everyone and add revenue by gradually increasing your members’ skills.
It also allows for shorter, more customised training fitting every goal and ambitions of each diver. Do you live in a region with amazing wrecks at around 30-40m deep? Are you only diving with your instructor friends? Let’s give you a wreck and deep dive course and let’s keep the other things for later.
While this is a great way to learn pedagogically, it can make the non-profit organizations (who still promote a more “universal knowledge” type of teaching) raise their eyebrows.
And it tends to become a nightmare when establishing a unified scale to evaluate skill levels and create equivalencies between organizations.
Diving Certification Levels - What types of skills?
To make sense of all the diving certifications out there and try to establish a reference system for equivalency we can refer to the standardisation bodies like the International Organization for Standardisation, (ISO), who developed three qualification levels.
These norms have been established by teams of international experts and are now used as a reference by all major organizations.
Their conclusion was that scuba diving levels and competencies could be divided into three main skill sets.
The first is being able to dive safely while being entirely supervised and in a no decompression environment.
The second is to dive without supervision in a no decompression environment with divers of your level or higher.
And the third is being able to lead & guide safely divers with less experience in a wide range of conditions.
Below are the details of the content for each of these certifications:
ISO 24801-1: The Supervised Diver
PADI Scuba Diver, SSI Scuba Diver, NAUI Passport Diver, SDI Supervised Diver
What skills should you have?
- Use mask, fins & snorkel
- Assemble and disassemble your gear
- Enter & leave the water
- Clear your mouthpiece underwater
- Share a regulator while swimming at the surface
- Go down and up properly & easily (equalization, etc.)
- Swim underwater
- Clear your mask underwater
- Control your buoyancy underwater and on the surface
- Recover your regulator underwater
- Monitor your air consumption and depth
- Quickly release your weight on the surface
- Breathe through someone else’s regulator or octopus
- Take care of your gear
- Use basic hand signals
What should you know ?
- How to use and maintain your equipment: Fins, Mask, Snorkel, Regulator, Octopus, Tanks, BCD, Weights, Pressure Gauge, Dive Computer or Tables, Diving Suit
- The effects of changing pressure on the body when going down and when going up. In your ears, lungs, sinuses, stomach, teeth, etc..
- The effect of changing pressure on your dive such as equalization, buoyancy & air consumption.
- Other risks such as stress, temperatures & alcohol
- Basic knowledge of your environment, your impact on it and its impact on your dive
- What to do in case you are separated from your group.
ISO 24801-2: Autonomous Diver
PADI Open Water, SSI Open Water, NAUI Open Water, SDI Open Water, BSAC Ocean Diver, CMAS *
What skills should you have?
- Inspect your gear and your buddy’s before the dive
- Choose the proper amount of weight
- Swim underwater with great buoyancy & control of your body
- Clear & Take off your mask underwater
- Breathe underwater without your mask
- Use and monitor your diving computer
- Simulate an emergency ascent with an out of air situation, both receiving and giving air to your buddy.
- Simple underwater navigation
What should you know?
- How to use and take care of your equipment including: Float, flag and marker buoy, cylinder valves, timing devices, compass, depth monitor, knife, lights, emergency signal device, first aid and oxygen kit, diving log
- Physics concepts applied to scuba diving such as pressure and gas laws and their relationship with temperature as well as buoyancy and the effects of water and depth on sounds and light.
- How to manage decompression using dive tables & computers such as choosing the right dive profiles to stay within the no-decompression limit for single or repetitive dives.
- How to plan a dive excursion with your buddy including the emergency procedures, diving from a boat, handle communications & your diving log.
- Diving medical problems, including narcosis, oxygen toxicity, hypercapnia and contaminated gas.
- Diving environment including the impact of altitude, fresh vs salty water, temperature and thermoclines, visibility and currents. Your local environment and ecosystem including how to preserve it and the risks involved.
- You should be able to perform CPR and give oxygen first aid at sea level
- You should know the risks involved with other factors like fatigue, hypothermia, hyperventilation, medication and alcohol
- You should know how to identify and deal with stress, panic and overconfidence
ISO 24801-3: Dive Leader
PADI Divemaster, SSI Divemaster, NAUI Divemaster, SDI Divemaster, BSAC Dive Leader, CMAS ***
What skills should you have?
You should be able to demonstrate complete mastery of the skills learned in previous levels. Especially in the following areas:
- Complete mastery of buoyancy
- Complete mastery over your diving instrument (deep understanding of your diving computers settings & modes)
- You should be able to perform a mid-intensity swim on the surface with all your gear
- You should be able to remove and replace and adjust your weights and the ones from the divers with you.
- You should have complete mastery over the emergency ascent procedures in case of “out-of-gas”, narcosis, or strong out of breath situation.
- You should have a deep understanding of diving equipment and the proper maintenance
- You should in all cases be able to navigate confidently underwater
Moreover, the Dive Leader should have experience and completely master skills regarding:
Deep Diving:
- Narcosis
- Air consumption
- Decompressions Limits
- Ascent Procedures including in water stops
- Buoyancy Changes
- Emergency Gear & Procedures
Leadership:
- Dive related skills such as planning, briefing, skills assessments, post dive briefing, etc…
- Rescue related skills such as underwater search, emergency actions in surface, controlled recovery, etc..
- First Aid, CPR & Oxygen administration
What should you know?
You should be able to demonstrate a complete understanding of the concepts learned in previous levels. With additional knowledge required in the following areas:
- Equipment mechanics & inner works such as the different algorithms in computers or the mechanics of a 2 stages regulator.
- Physics applied to diving including the relationships between pressure, temperatures, the toxicity of gas, partial pressure, etc…
- Medical aspects of scuba diving with a deep understanding of the physiology applied to diving: ear, vascular system, nervous system, respiratory system. You should be able to explain in details the impacts of changing pressure and the water environment on each and describe all possible illness and accidents related to diving.
- Deep understanding of your diving environment including currents, tides, visibility, thermoclines and the ecosystems around you.
- You should be able to demonstrate your ability to lead & plan a dive excursion, detailing the procedures and the communications with both the surface and the divers underwater.
- You should know by heart the recommended diving practices for safety
You should also know the procedures, best practices and risks involved with:
- Diving from a boat
- Diving at night
- Diving with limited visibility
- Deep diving
- Diving with currents & tides
- Diving in caves & wrecks
- Lost divers
Finally, you should have an understanding of the legal requirements associated with scuba diving.
How much diving experience do you need?
To be certified as a scuba diver level 3, you should have logged at least 60 open water dives or 50 open water dives with a total accumulated underwater time of 25 h.
At least 40 of these dives should have been completed after level 2 in accordance with ISO 24801-2.
At least 30 open water dives shall include as wide a range of environmental factors as possible to ensure that the student has a wide range of experience.
Examples of more demanding environmental factors can be:
- low visibility (less than 2 m horizontal)
- currents (more than 0,25 m/s (approximately half a knot))
- cold water (less than 10 °C).
If you don’t have this type of conditions available around you, you will have to do more dive than required and include more deep dives (more than 30m).
Diving Certification Equivalency - Comparative Table
Now that we know the international standards, we can try to compile together all the different certifications from the major diving organizations and build a visual representation of the equivalencies theoretically available.
Of course, the following table is just a reference to visualise, and organizations might have their own policies about equivalencies. It is ultimately the instructor or dive director who has the final word on the matter, and they will decide on the moment if you are allowed to go on that deep dive or not.
This can give us an idea of the equivalencies between the different diving agencies, however as you can see, the ISO standards seem to have a gap between the Autonomous Diver and the Dive Leader which is difficult to fill in uniformly.
While you can be relatively confident in the equivalence in skills between a PADI Open Water and a CMAS *, the speciality system and the rules of each agency makes it difficult to compare an Advanced Open Water with a CMAS** for instance.
To give you an idea, I personally learned how to dive with CMAS, more precisely with the french federation before doing my Divemaster with PADI in order to find work when travelling.
I was able to pass my Level 2 (CMAS**) at 16 years old, and this training allowed me to dive on any type of conditions to a depth limit of 40 meters while guided by a dive leader and up to 20m when diving autonomously. This included an emergency ascent from 40 m simulating “out of gas” and extensive training on how to use a parachute and perform decompression stops.
If we try to find the parallel with PADI, we will have to combine an Advanced Open Water with a Deep Dive speciality to go up to 40m, but PADI doesn’t allow decompression stops and divers will have to stay within the no-decompression limits. However, the advanced open water will be allowed to dive autonomously to 30m which is not allowed for the CMAS**.
When advancing to the rescue diver programs, we find again some difficulties in establishing equivalencies. While every rescue course cover more or less the same main topics and procedures like first aid and oxygen administration, the difference can become quite big when taken into account the depth limits allowed by the organisations and most importantly the presence of decompression stops.
For example, the level 3 of the French federation allows for autonomous dives to the limit of air diving at 60 m, and as such a perfectly skilled PADI rescue diver who never did decompressions stops will not be fully equipped to perform rescue procedures at 50m when 12 min of decompressions stops are showing up on the computer.
