SCUBA Travel

Equivalent Diving Qualifications from Different Agencies

24 November 2015
There are many different bodies around the world which award diving qualifications. This table gives a rough guide to equivalent qualifications. It is only a guide though: the qualifications are not exactly equivalent. Please contact your chosen diving agency for their definitive crossover requirements.

The maximum depth guides are all on air. Some grades can go deeper than stated with additional training. Any questions? Get in touch. For instructor grades see below.

Equivalent Diving Qualifications from different SCUBA Agencies

Dive AgencyDiving Qualifications
CMAS1 Star
20 m
1 Star
20 m
2 Star
40 m
2 Star
40 m
3 Star
56 m
4 Star
BSACOcean Diver
20 m
Ocean Diver
20 m
Sports Diver
20 m
(35 m after progress dives)
Dive Leader
50 m
Advanced Diver
50 m
1st Class Diver
PADIOpen Water Diver
18 m (12 m if under 12)
Advanced Open Water Diver
30 m
Rescue DiverDivemaster
35 m (40 m with Deep Diver)
35 m (40 m with Deep Diver)
NAUIScuba Diver
18 m
Advanced Scuba DiverScuba Rescue Diver / Master Scuba DiverDivemaster1
SAAOpen Water Diver
20 m
Open Water Diver
20 m
Club Diver
35 m
Dive LeaderDive Supervisor 1 - Dive Master
SSIOpen Water Diver
18 m
Advanced Adventurer
Advanced Adventurer DiverAdvanced Open Water Diver with "Stress and Rescue" Speciality or Master DiverDive Control Specialist
Open Water DiverAdvanced Open Water DiverRescue DiverDive Supervisor
SDIOpen Water Diver
20 m
Advanced DiverRescue DiverDivemaster
SSAC (ScotSAC)Sports Diver
30 m
Master Diver
40 m
Second Class Diver / Master Diver 1
Royal NavyShips Diver
ITDA2** Star DiverAdvanced Nitrox DiverITDA Rescue Diver Extended Range Nitrox Diver (Ntech)
ANDIOpen Water DiverRescue DiverDivemaster
GUEAll GUE qualifications
IANTDOpen Water Diver
21 m
Essentials DiverAdvanced Open Water Diver
30 m
Rescue DiverDivemaster
DMT NASE UKOpen Water Diver
20 m
Advanced Open Water Diver
30 m
Rescue DiverAdvanced Rescue DiverDivemaster
PSAIOpen Water Sport Diver
18 m
Advanced Open Water Diver
27 m with 5 specialities2
R.A.P.I.D. Master Diver
27 m3
Advanced Deep Air Level 1Divemaster
40 m
TDIAdvanced NitroxExtended Range
LA Co UWBasic CertificationIntermediate CertificationAdvanced Certification
PDICOpen WaterAdvanced Open Water Diver
IADS1 Star Open Water Diver
20 m
2 Star Advanced Diver
32 m
Intermediate CertificationAdvanced Certification
IDDOpen Water Diver
20 m
Advanced Open Water Diver
32 m
HSEHSE Commercial Diver: HSE Scuba Diver/HSE Surface Supply Diver/ HSE Surface Supply (Top Up) Diver/HSE Closed Bell Diver (formerly HSE Diver Part 4, 3, 1 and 2 respectively)


As a rough guide, if you have a qualification from one agency you will be allowed to enroll in the equivalent next course up from another agency - assuming you have the relevant diving experience. See the references below for more information about individual agencies.

Instructor Grades

Dive AgencyInstructor Qualifications
CMAS1 Star Instructor2 Star Instructor3 Star Instructor4 Star
BSACClub InstructorOpen Water InstructorAdvanced InstructorNational Instructor
PADIOpen Water Scuba Instructor (OWSI)Master Scuba Diver Trainer (MSDT)Instructor Development Course (IDC) Staff Instructor
NAUIScuba InstructorInstructor TrainerCourse Director
SAAClub InstructorRegional Instructor
SSIOpen Water Instructor
SSAC (ScotSAC)Branch InstructorRegional InstructorClub Examiner
LA Co UWUICC (underwater instructors certification course)
ITDA Resort Instructor 2** STAR Instructor2** STAR Instructor
IADSUICC (underwater instructors certification course)


BSAC and PADI divers

The above tables are by no means exhaustive: there are other training agencies and qualifications. If you plan to cross-over training, you may be asked to start a level down from your equivalent qualification. Ask your new agency for advice.

American Nitrox Divers International. specialise in training programs for technical diving and closed circuit rebreather systems.
British Sub-Aqua Club. The BSAC is the governing body for the sport of scuba diving in the UK. It is a club-based organisation that offers training for members through a branch, or intensive courses through a BSAC school. BSAC was established in 1953 by Oscar Gugen.
Confédération Mondiale des Activites Subaquatiques (World Underwater Federation of Underwater Activities). Established 1959.
No association with NASE or NASE Europe. The DMT Training Group researched, developed and implemented the programmes in the UK and Canada and were the first Agency Accredited by HSE under the updated DWR 1997 Regulations in 2000 and were accredited by HSE in January 2001. Since that time DMT NASE UK has been accredited annually, with new programmes being submitted on a regular basis.
Global Underwater Explorers. Non-profit organisation dedicated to the training of divers as well as the study and protection of the aquatic realm.
Instructor Dive Development. Established in 1992 in Europe with its Head-Office in Amsterdam, The Netherlands. IDD wanted an education which could be used not only in tropical waters or cold European waters, but truly could be used effectively all over the world.
International Association of Diving Schools.
International Association of Nitrox and Technical Divers. UK organisation offering training courses from Open Water Diver through to Expedition Trimix.
International Technical Diving Agency.
LA County Scuba Underwater Programs. First American training agency: established 1954.
Military Divers
PADI recognises military diver qualifications as a pre-requisite to many of its courses, but doesn't offer a straightforward crossover. So you could, for example, take a rescue divers course without having previously done a PADI advance open water course.
National Association of Scuba Diving Schools: now merged with SSI.
National Association of Scuba Educators. American-based. Draws its extensive experience from the fields of commercial, recreational, technical and cave diver training. No association with DMT NASE UK LTD.
NASE Europe
National Association of Scuba Educators Europe. No association with DMT NASE UK LTD.
National Association of Underwater Instructors. Worldwide organisation headquartered in America.
Professional Association of Diving Instructors. Worldwide organisation headquartered in America.
Professional Diving Instructors Corporation. Founded in the USA in the 1960s.
Professional SCUBA Association International. The oldest technical / extended range scuba certification agency.
2Narcosis Management Level I or Deep Diver speciality inclusion extends depth limit of Advanced Open Water Diver to 30m.
3Narcosis Management Level II speciality inclusion extends depth limit of R.A.P.I.D. Master Diver to 40 m.
Rebreather Association of International Divers. Rebreather and open circuit training. Use an e-learning programme. RAID training standards are compliant with ISO Recreational Diving Standards and is accepted by The UK Health and Safety Executive as an approved provider. They also offer Nationally Accredited training in Australia.
Sub-Aqua Association. British organisation.
Scuba Diving International. Created in 1999 and grew out of sister company TDI, which specialises in the more advanced disciplines of technical dive training. Agencies that are accepted to meet the prerequisites for SDI include: IDEA, PADI, PDIC, SSI, YMCA, NAUI, BSAC, Sub Aqua Association, European Standard, CMAS and IANTD
Scottish Sub-Aqua Club. Founded in 1953. Like the BSAC it is a club-based organisation offering thorough training for Scottish conditions.
Scuba Schools International. In the Spring of 1999, SSI merged with the National Association of Scuba Diving Schools.
Technical Diving International. Agencies that are accepted to meet the prerequisites for TDI include: IANTD, ANDI, DSATI, SSI, NAUI, NACD, NSS-CDS, CMAS, BSAC and CDAA.

Sources: BSAC T.17, HSE, SDI TDI ERDI, CMAS International Diver Training Standards and Procedures Manual, e-mail from PSAI Europe, e-mail from DMT NASE UK Ltd / DMT Training Group, CMAS-PADI agreement, BSAC Information for Divers Crossing Over from PADI, SSI, SSAC & SAA.

by Jill Studholme

Over to You

If you have any comments or questions, please fill out this form or use the Facebook comments box.

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5 Star Rating: Recommended (270 users, 4.8)

Is there any PADI SCUBA certification recognized by IMCA to do DMT course? Which level if any?
, 24 November 2015
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IMCA stands for International Marine Contractors Association and DMT for Diver Medic Technician. The DMT course is for surface cover team members, who are not diving, to be trained in advanced first aid. To gain the IMCA DMT certification as an offshore diver, you must hold an IMCA qualification (or equivalent) in offshore diving. The equivalent qualifications are for commercial divers, so no PADI courses would be suitable.
There are also DAN Recreational Diver Medic Technician courses run for recreational divers, but these are not accredited by the International Marine Contractors Association. To participate in this course you must have the equivalent (or higher) of a rescue diver certification.
Jill Studholme, SCUBA Travel

Is there an organisation called EIND offering diving certification courses, especially in Greece?
, 22 October 2015
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Hi Bob
We haven't heard of EIND and can find no reference to it on the internet. Do you know what the acronym stands for?
SCUBA Travel

Hey :) this Website is really helpful, but it left open my question. I have the cmas*, now I am wondering if it is possible for me to do the SSI open water advanced including adventure dives like night dive, current dive, deep dive.. (I think it's like the cmas**?)AND if it is then possible to do the cmas*** regularly back in Germany? Couldn't find any answers to this.
Thanks for your help! :)

, 17 October 2015
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Hi Theresa
You are probably best contacting a CMAS dive centre to check their requirements. Normally you would need the equivalent of CMAS 2 star + Oxygen Administration, Rescue Diver and 50 logged dives including night, limited visibility, dives deeper than 30 m, drift dives, cold water and navigation. Which may mean the SSI Diver Control Specialist level as well as the specialist dives.
Jill Studholme, SCUBA Travel

When applying for the Royal Navy do they have any preference as to which qualification would be best?
, 16 July 2015
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Hi Jack
The Navy run their own training programme - you don't need to already be able to dive.
SCUBA Travel

Will the bsac ocean diver qualify you to do padi advanced open water diver with out having to do padi open water course?
, 29 June 2015
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Hi Ben
Yes, you will be able to enroll in the PADI advanced course.
Jill Studholme, SCUBA Travel

Greetings from Greece. All these are very helpful and completely understanding but my finally question is specific. Which certification is "better" for dive master, padi or andi?
, 28 June 2015
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Hi Dionisis
Unless you want to specialise in technical diving PADI is a better option to choose.
Jill Studholme, SCUBA Travel

I have my NASDS open water certification and am going to take an advance PADI course. Is there any reason they will not acknowledge my NASDS OW certification?
, 25 June 2015
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Hi Emilio
There is no reason why they shouldn't, but check with the company you are planning to train with to make sure.
Jill Studholme, SCUBA Travel

Since when has a PADI Divemaster been qualified to 35m? If they hold the PADI Deep spec it is 40m, otherwise 35m
, 24 June 2015
4 Star Rating: Recommended (4*)

Hi Pee
We'll amend the table to include the Deep Diver course.
Jill Studholme, SCUBA Travel

Voilà, je suis instructeur OWSI PADI et je certifie mes élèves en leur fournissant des certification PADI, je rencontre parfois certaines requêtes émanant de certains de mes élèves qui désire obtenir l'équivalence CMAS et bien entendu aussi le PADI et je cherche actuellement comment rendre cela possible.
En bref, je voudrai leur obtenir l'équivalence de leur certification PADI en un autre brevet CMAS, combien cela me couterait il et comment y procéder?
(Which translates as "Well, I'm OWSI PADI Instructor and certify my students by providing PADI certification, I sometimes meet some requests from some of my students wishing to obtain the CMAS equivalence and also the PADI course and I'm currently looking how to make it possible.
In short , I want them to get the equivalence of their PADI certification in another patent CMAS , how much it cost me and how to get them?")
, 23 June 2015
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Hi Adil
You can't get an equivalent CMAS card for a PADI qualification. Your students would have to do an extra course with CMAS. Which level they could go in at is defined in the CMAS - PADI agreement. Other agencies though, like BSAC, do issue CMAS cards.
Jill Studholme, SCUBA Travel

1) Different between dive tech. and dive master
2) Which among them is the best to know or study

, 18 June 2015
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Not sure what you mean by dive tech. Which to study depends somewhat on where you will be diving. With a program like BSAC you get a more thorough grounding than with a PADI Open Water course, but it takes longer. Find out what is available in your area, contact the dive shops and make your choice.
SCUBA Travel

I have many years of diving experience with HSE part 1 11, Military advanced diver from Royal Engineers, I have dived and worked all over the world and yet to convert to PADI. It seems all this experience and qualification has no transferable meaning.
, 25 May 2015
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Hello Mark
Many dive shops do recognise HSE. BSAC clubs, for example, recognise HSE part 1 as equivalent to BSAC Sports Diver. If you joined BSAC you could apply for an 'Equivalency Card' from BSAC HQ. This would be recognised by PADI dive centres even if your HSE qualification wasn't. (Although PADI shops should recognise your HSE qualification as equivalent to Rescue Diver.)
Jill Studholme, SCUBA Travel

I hold a UK HSE Part one from 1988 and an IMCA air diving supervisors qualification from 1993. How best would I prepare papers for holiday diving
, 11 May 2015
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Hi David
The best thing to do is to contact dive centres in the area in which you are planning to dive and ask what they need. Your recent diving experience is often more important than which diving agency you qualified with.
Jill Studholme, SCUBA Travel

In your table you forgot the level NAUI Instructor Trainer and NAUI Course Director
, 29 April 2015
5 Star Rating: Recommended (2*)

We've added them to the table.
SCUBA Travel

I am certified with RAID, but this is not on your table.
, 19 March 2015
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Thanks for pointing that out Nicole. We'll add them to the table.
Jill Studholme, SCUBA Travel

Regarding diving outside the UK with a hse scuba, this was absolutely no problem for my friend on a recent diving trip to Thailand. Recognised at shops both in Koh Tao and Koh Phi Phi.
, 3 March 2015
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Is this cross-over list officially world wide recognised?
, 16 January 2015
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Hi Robert, No, there isn't an official world-wide crossover list. Ours is compiled from publications from: BSAC T.17, HSE, SDI TDI ERDI, CMAS International Diver Training Standards and Procedures Manual and direct communication with PSAI Europe and DMT NASE UK Ltd / DMT Training Group. Jill Studholme, SCUBA Travel

I am a IANTD advanced nitrox diver so what am I in the flow chart thank you
, 15 December 2014
5 Star Rating: Recommended (5*)

Hi John, You'd have to contact the alternative agency to be sure, but around BSAC Dive Leader with a nitrox speciality.
SCUBA Travel

I was wondering, do you know if with my CMAS 2* licence I can take the Dive Master course?
, 16 September 2014
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Yes, you are at the right level to take the PADI or NAUI Divemaster course.
Jill Studholme, SCUBA Travel

Hi I'm a BSAC Openwater instructor and I would like to know what are the procedures if I want do become a PADI Instructor!
, 16 September 2014
5 Star Rating: Recommended (5*)

Hi Shyam, you can't just transfert to PADI - you always have to do one of their courses. In your case a PADI Instructor Development Course would be appropriate.
SCUBA Travel

Thank you for your follow-up regarding the listing.
NASE are not operating within the United Kingdom. The programmes listed by HSE and ACCREDITED by HSE are copyright of DMT NASE UK LTD.
NASE Europe is a separate entity and DO NOT have any rights to teach or certify persons in the designated programmes. We have in the past had working arrangements with NASE Europe, but these have since lapsed.
NASE in the USA is a separate entity and we NO working relationship with them.
The DMT Training Group researched, developed and implemented the programmes in the UK and Canada and were the first Agency Accredited by HSE under the updated DWR 1997 Regulations in 2000 and were accredited by HSE in January 2001.
Since that time DMT NASE UK has been accredited annually, with new programmes being submitted on a regular basis.
If you review the HSE web site, you will see that only DMT NASE is listed as APPROVED, not the other NASE entities.
I would be pleased to provide you with a complete list of the programmes recognised by HSE that DMT NASE offer.

Kindest regards,

, 3 August 2014

Thanks very much for that
SCUBA Travel

Is there a special certificate for a handicapped / disabled diver?
, 24 April 2014
5 Star Rating: Recommended (5*)

As far as I'm aware there isn't a special certificate for disabled divers, but we'll ask on our social media pages and in our next newsletter to see if our readers know of any. You might be interested in an article by Dave Thompson on learning to dive as a tetraplegic which we published in issue 122 of SCUBA News. Dave qualified as a PADI Open Water Scuba Diver.
Jill Studholme, SCUBA Travel

I'm a qualified to HSE scuba and Police Surface supplied as I am a Police diver. I am due to go on my Honeymoon and wish to take part in recreational diving. My partner is going to do a PADI course. I was wondering how well recognised my qualification is. Would it be recognised abroad easily. What would it equate to as a PADI qualification and how easy would it be for me to get PADI qualifications with the qualifications I already have. Thanks
, 10 April 2014
5 Star Rating: Recommended (4*)

HSE Scuba equates to BSAC Sports Diver or PADI Rescue Diver. You need to contact the dive centre you will be using to confirm that they will understand your qualification. There should be no problem converting to a PADI qualification - but you will have to do one of their courses. Anyone else had experience of using an HSE qualification outside Britain?
SCUBA Travel

I have a PDIC certification. Have you ever heard of this?
, 2 April 2014
5 Star Rating: Recommended (5*)

I have heard of it and see it is not in our table - I'll add it.
Jill Studholme, SCUBA Travel

I'm a naui master scuba diver can i crossover to padi.what level will i be.
, 17 March 2014
5 Star Rating: Recommended (5*)

A NAUI Master SCUBA Diver is equivalent to a PADI Rescue Diver. So you would be qualifed to take the PADI Divemaster course.
Jill Studholme, SCUBA Travel

Certified with US Navy Diver Certification - extensive military certification. Since I dive mostly in warm salt water, how do I convert to PADI without going through the entire PADI certification process?
, 26 February 2014
5 Star Rating: Recommended (5*)

You don't need to do the entire process but will need to do one course, for example the rescue diver. PADI will accept your qualifications as a pre-requisite for the course, but will still insist you take it before giving you a PADI certification card.
Jill Studholme, SCUBA Travel

Where is PSAI Advanced Oper Water Diver?
, 27 January 2014
5 Star Rating: Recommended (5*)

I'm not sure about where exactly to place PSAI Advanced Open Water Diver - looking at what's involved I should think CMAS 2 star. I'll contact the PSAI though, and see what they say.
Jill Studholme, SCUBA Travel

It appears that Naui Master diver and SSI Master diver are in the incorrect order. I believe neither of these are professional qualifications.
Naui master diver may be accepted as PADI rescue if the rescue components are taught in that course. SSI dive controller and PADI Dive master are equivalant. Can you confirm please?
, 12 November 2013
5 Star Rating: Recommended (5*)

Thanks for pointing that out. We've moved them to a more appropriate position.
SCUBA Travel Webmaster

The listings for SSI don't include the instructor levels and the recreation diver levels are little off. After OW is specialty diver 12 dives and 2 specialties, then AOW diver 24 dives and 4 specialties, then Master Diver AOW plus Stress Rescue Diver and 50 dives. The pro levels can be found on to add to your table.
, 9 August 2013
5 Star Rating: Recommended (5*)

Thanks Beth, we'll update the page.
SCUBA Travel Webmaster

This table is very useful for roughly equivalent qualifications, however, I have found that the maximum depth ratings can vary. Has anyone compiled a table with depth limits between the differing qualifications?
, 8 August 2013
5 Star Rating: Recommended (5*)

Good point. We'll look at adding maximum depths.
SCUBA Travel Webmaster

Two BSAC grades are missing: Ist Class Diver (4 star) and National instructor (4 star).
, 20 July 2013

5 Star Rating: Recommended (5*)

Thanks for the getting in touch - we've inserted 2 new columns for the 4 star grades.
SCUBA Travel Webmaster

Does not include the world's first Instruction program--LA Co UW Instruction program; Basic Diver, Advanced diver (100 + Hours,) Instructor UICC, 200 hours.
, 16 July 2013

3 Star Rating (3*)

Thanks for the info - we've added LA Co UW.
SCUBA Travel Webmaster

Please note the information you display about ITDA is out of date... please see: or our support site at
Thank you
, 11 July 2013
5 Star Rating: Recommended (5*)

Thanks for letting us know Steve - we've now updated the page.
SCUBA Travel Webmaster

Recommended Training Books

The Complete Diver: The History, Science and Practice of Scuba Diving
by Dr Alex Brylske, 2012
A comprehensive guide to recreational scuba diving.
The Diving Manual
Circle Books, Paperback, 164 pages, (2002).
One from the British Sub-Aqua Club. Aimed at those interested in taking up diving, and written with the forthcoming European Diver Training Standards in mind, besides supporting divers following the BSAC system this generic diving manual will also be useful to divers following other training systems.
NOAA Diving Manual: Diving for Science and Technology, Fourth Edition
James T. Joiner, Best Pub Co, Hardback, 660 pages, (2002).
One of the most detailed diving reference books available and is a valuable resource for all who are interested in a complete encyclopedia of diving technology, equipment, techniques and procedures.
Scuba Professional: Insights Into Sport Diver Training and Operations
Simon Pridmore, 304 pages, 1 edition (July 17, 2015).
New book looks at how diving is taught and gives independent, objective advice for instructors and dive operators. It includes a chapter on "Which Training Agency?", which is a question we are often asked.