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Equivalent Diving Qualifications from Different Agencies


10 July 2014
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 below.

BSACOcean Diver
20 m
Ocean Diver
20 m
Sports Diver
30 m
Dive Leader
50 m
Advanced Diver
50 m
Club InstructorOpen Water InstructorAdvanced Instructor1st Class DiverNational Instructor
PADIOpen Water Diver
18 m (12 m if under 12)
Advanced Open Water Diver
30 m
Rescue DiverDivemaster
35 m 1
35 m
Open Water Scuba Instructor (OWSI)Master Scuba Diver Trainer (MSDT)Instructor Development Course (IDC) Staff Instructor
CMAS1 Star
20 m
1 Star
20 m
2 Star
40 m
2 Star
40 m
3 Star
56 m
1 Star Instructor2 Star Instructor3 Star Instructor4 Star4 Star
NAUIScuba Diver
18 m
Advanced Scuba DiverScuba Rescue Diver / Master Scuba DiverDivemaster1 Scuba Instructor
SAAOpen Water Diver
20 m
Open Water Diver
20 m
Club Diver
35 m
Dive LeaderDive Supervisor 1 - Dive MasterClub InstructorRegional Instructor
SSIOpen Water Diver
12 m
Advanced Open Water DiverAdvanced Open Water Diver with "Stress and Rescue" Speciality or Master DiverDive Control SpecialistOpen Water Instructor
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 1Branch InstructorRegional InstructorClub Examiner
Royal NavyShips Diver
ITDA2** Star DiverAdvanced Nitrox DiverITDA Rescue Diver Extended Range Nitrox Diver (Ntech) Resort Instructor 2** STAR Instructor2** STAR Instructor
ANDIOpen Water DiverRescue DiverDivemaster
GUEAll GUE qualifications
IANTDOpen Water Diver
21 m
Essentials DiverAdvanced Open Water Diver
30 m
Rescue DiverDivemaster
NASEOpen 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. (Rescue, Accident Prevention & Intervention Diver) Master Diver
27 m3
Advanced Deep Air Level 1Divemaster
40 m
TDIAdvanced NitroxExtended Range
LA Co UWBasic CertificationIntermediate CertificationAdvanced CertificationUICC (underwater instructors certification course)
PDICOpen WaterAdvanced Open Water Diver
IADS1 Star Open Water Diver
20 m
2 Star Advanced Diver
32 m
Intermediate CertificationAdvanced CertificationUICC (underwater instructors certification course)
IDDOpen Water Diver
20 m
Advanced Open Water Diver
32 m


BSAC and PADI divers

The above table is 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.
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. Draws its extensive experience from the fields of commercial, recreational, technical and cave diver training.
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.
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.

by Jill Studholme

Over to You

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

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5 Star Rating: Recommended (47 users, 4.9)

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 controler and PADI Dive master are equivelant. 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 Books for Beginners

The Complete Diver: The History, Science and Practice of Scuba Diving
by Dr Alex Brylske, 2012
A comprehensive guide to recreational scuba diving.
Available from UK
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.
Available from UK
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.
Available from UK (but cheaper from USA)
PADI Manual

Available from and Click here for details.