Commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC

Why there are five answers and not one

Commercial diving is regulated nationally and worked internationally. That mismatch is the whole story.

Every country with a diving industry wrote its own rules, and most of them tied the right to dive for pay to a qualification issued or approved by the state. Great Britain did it through regulation 12 of the Diving at Work Regulations 1997, which says a diver may not dive in a diving project unless they hold an approved qualification valid for the work they can reasonably expect to do, plus a valid certificate of medical fitness. Australia built the Australian Diver Accreditation Scheme in 1988 as a Commonwealth government initiative. Canada created a national certifying board. Norway certifies through its offshore regulator.

The United States did not. There is no federal diver licence, and no state one either. What exists instead is a trade association card and a training standard.

Then the work went offshore, where the employer is a contractor operating from a vessel that may be flagged anywhere and working in anyone's waters. The contractors' own association, IMCA, ended up as the de facto gatekeeper for offshore diving — not by certifying divers, but by publishing which national certificates its members will accept. So the question "which certification do I need" has two layers: which ticket the country you work in demands, and which ticket the contractor who employs you will accept.

Those two layers do not line up neatly, and the gaps between them are where careers stall. We cover the decision itself in more depth in our guide to choosing between HSE, IMCA, ADCI, ADAS and DCBC, but this page is the reference: who issues what, who accepts it, and what it costs.

The five schemes, described accurately

HSE (United Kingdom). The Health and Safety Executive does not run courses. It approves qualifications and it approves the organisations that assess competence. Its List of Approved Diving Qualifications is a regulatory instrument, issued under regulation 14(1) and signed by HM Chief Inspector of Diving; the current edition is dated 1 January 2026. The commercial ladder is four certificates: SCUBA, Surface Supplied, Surface Supplied (Top-Up), and Closed Bell. The Top-Up is the gate to offshore surface-supplied work, and Closed Bell covers mixed gas below 50 metres. As of February 2026 HSE listed twelve recognised competence assessment organisations, of which only two — Commercial Diver Training Ltd and The Professional Diving Academy — cover the full air diving ladder including the Top-Up.

ADAS (Australia). Developed by the Commonwealth Government in 1988 and run by a board of directors under a memorandum of understanding with the federal industry department, on a cost-recovery, not-for-profit basis. Certification maps to the AS 2815 series: Part 1 occupational SCUBA to 30 m, Part 2 surface-supplied to 30 m, Part 3 surface-supplied to 50 m, Part 4 closed bell, Part 5 supervisor, Part 6 restricted SCUBA. ADAS accredits training establishments rather than delivering training itself, and it accredits them outside Australia: for Part 1 alone, twelve schools in six countries, including Barcelona, Istanbul, Singapore, Kemaman and two in New Zealand. You can hold an Australian ticket without having been to Australia.

DCBC (Canada). The Diver Certification Board of Canada certifies against CSA Z275.4, the Canadian competency standard for diving. DCBC states that its certification is legislated in eight of the ten provinces and that everyone diving in Canada's offshore must carry it. The offshore regulations themselves are less direct than the board's summary: section 172(1)(b) of the Canada–Newfoundland and Labrador Offshore Area Occupational Health and Safety Regulations requires each dive team member to conform to the competencies in CSA Z275.4 without naming DCBC. In practice DCBC is the body that certifies to that standard.

ADCI (United States). The Association of Diving Contractors International was founded in 1968 and chartered in 1970. It is a non-profit, non-governmental body that publishes the Consensus Standards for Commercial Diving and Underwater Operations and issues certification cards: Tender, Air Diver, Mixed-Gas Diver, Bell/Sat Diver, and the matching supervisor grades, plus Life Support Technician and a nitrox endorsement. It is not a regulator and the card is not a licence. OSHA's own position, in a letter of interpretation dated 29 March 2000, is blunt: "There are no commercial diver licensing programs in the United States." OSHA treats a valid ADCI card as one way to show compliance with 29 CFR 1910.410, alongside training at a state, military or federal school, or at an ACDE-accredited school. That letter is now in OSHA's archive and carries a notice that it may no longer reflect current policy, so read it as the position of record in 2000 rather than today's.

IMCA (international, contractor-side). The International Marine Contractors Association certifies Diving Supervisors, Life Support Technicians and Diving System Inspectors, and runs a mandatory CPD scheme for supervisors. It does not certify divers. What it does instead is publish the list of diver certificates it will accept for offshore diving under its code of practice, IMCA D014. If your ticket is not on that list, you are not an offshore diver as far as an IMCA member contractor is concerned, whatever your logbook says. Our explainer on what IMCA is and why it matters covers the association's wider role.

The five schemes at a glance

Sources: HSE List of Approved Diving Qualifications, 1 January 2026; ADAS Fees Overview, updated 4 June 2025; DCBC Certification; O*NET certification record, ADCI Air Diver; IMCA, Diving certification.

Who recognises whom: the map nobody publishes

This is the part every other page gets wrong, usually by implying a tidy web of mutual recognition. There isn't one. There is a forum — the International Diving Regulators and Certifiers Forum, which confirmed its principles at a London meeting in September 2009 — whose stated aim is to pursue mutual recognition. Aim, not achievement.

DCBC, a founding member, states on its own site that "DCBC certificates are recognized by all members of the IDRCF" and lists the members as Australia, Canada, France, Norway, South Africa, the United Kingdom, IMCA and ADCI. That claim is true in the direction DCBC cares about and misleading in the other. ADCI is an IDRCF member, yet an ADCI diver card appears on no other member's acceptance list. The traffic runs one way.

Here is what each body actually accepts, taken from each body's own published position:

Sources: HSE List of Approved Diving Qualifications, 1 January 2026; ADAS International Equivalents; DCBC Crossover; IMCA, Diving certification; IMCA IN 1415, 26 July 2018.

Two readings of that table matter. First, HSE, ADAS and DCBC form a working triangle: hold any one of the three at the right level and the other two will consider you, subject to paperwork. Second, the United States sits outside the triangle entirely, and the only bridges across are narrow and specific.

The American problem, stated plainly

If you train in the United States and intend to stay in the Gulf of Mexico or in US inland work, an ADCI card is the right document and the question ends there. Employers that are ADCI general members require their diving personnel to hold a current card matching their assigned tasks, obtained within 90 days of employment.

The publicly available sixth edition sets out what each entry grade costs in time.

Source: ADCI International Consensus Standards, sixth edition, record of changes dated 23 January 2025. Both grades also require an examination, current CPR and first aid, and a medical certification of fitness to dive.

If you intend to work in the North Sea, in Australia, in Canada's offshore, or on an IMCA member's vessel anywhere, the standard ADCI card does almost nothing for you. Three separate documents say so.

HSE's approved list, the 1 January 2026 edition, names overseas qualifications from Australia, Canada, Denmark, France, the Netherlands, Norway, South Africa, Belgium, Finland, Ireland, Italy, Poland, Portugal, Spain, Sweden and Northern Ireland. It does not mention the United States, ADCI, ACDE, or any American qualification. The only appearance of the word "American" on the list is American Nitrox Divers International UK Ltd, a UK-registered recreational agency.

ADAS's published list of recognised issuing bodies covers HSE, DCBC, France's INPP, Norway's Havtil, South Africa's Department of Labour, the Netherlands' NDC and IMCA for supervisor certificates. ADCI is not on it, and the page is explicit that even for the bodies that are listed, "not all certifications issued by the above organisations are automatically accepted by ADAS."

DCBC's crossover page names the acceptable foreign qualifications as Australia (ADAS), Norway and the United Kingdom (HSE), plus training at specified South African schools before 2010. ADCI is absent.

IMCA goes furthest, because it addressed the point directly. Information Note IN 1415, published 26 July 2018, states that IMCA recognises ADCI surface-supplied certificates only where the certificate bears the words "INTERNATIONAL ENDORSEMENT", and that no other ADCI diver training certificate is recognised for offshore diving under D014. IMCA also warned that presenting an ADCI surface-supplied certificate without that wording while claiming IMCA recognition misrepresents the holder's qualifications. At the time the note was written, no such endorsed certificates had yet been issued; they could be issued from 1 August 2018 onward, after assessment and top-up training delivered by two ADCI-approved US establishments to people resident in the United States.

The separate route that does work is ACDE. IMCA's December 2024 information note on diver and diving supervisor certification lists ACDE certificates issued since 1993 by accredited US schools under ANSI/ACDE-01-1993 and ANSI/ACDE-01-1998, with later diving experience evidenced in the logbook, among the certificates it recognises — and then closes the door: "No other diver training certificates are currently recognised by IMCA."

What each level actually permits, and to what depth

Depth caps are where schemes stop being interchangeable even when they are mutually recognised. A ticket that reads "surface supplied" in one country may be 30 m, 50 m or 70 m in another.

Sources: IDSA List of Equivalence 2025/2026, July 2025; ADAS Mutual Recognition Table v3.0, 11 December 2024; HSE List of Approved Diving Qualifications, 1 January 2026; ADAS Closed Bell (Part 4).

Note the oddity in the Canadian column. HSE lists "Surface Supplied Mixed Gas Diver to 70m" under a schedule heading that caps surface-supplied diving at 50 metres. The document does not reconcile the two, so if you hold that certificate and intend to work in the UK, ask HSE rather than assume.

Note also the restricted variants, which are the single most common source of unpleasant surprises. HSE's own footnotes spell out what "restricted" removes: an ADAS Part 3 Restricted holder "has not completed the ADAS wet bell, hot water suit and tool skill modules", and an ADAS Part 2 Restricted holder "has not completed the ADAS tool skill modules". A separate footnote, added to the 1 January 2026 edition, warns that ADAS qualifications do not include dry suit or nitrox training unless specified, and tells contractors to check for dry suit competency themselves. None of that is visible on the face of the certificate.

What it costs, from zero to an offshore ticket

Course prices are set by schools, not by certifying bodies. ADAS says so explicitly: initial training fees are paid to the training provider, and ADAS publishes only its own certification fees. Many ADAS and DCBC schools quote on application. The figures below are the ones actually published, in their own currency, at the date we consulted them.

Sources: Commercial Diver Training Ltd, The Professional Diving Academy, Divers Institute of Technology, DiveSafe International, DEEP; all consulted 8 October 2026.

Three honest caveats on that table. The DiveSafe figures are published without a currency label and without an effective date; the "+ GST" notes point to Canadian dollars, and we have marked them C$ on that basis. DIT's page lists its items without stating a total and says explicitly that the amount is the direct programme cost, not a budget — Seattle housing is extra. And none of the listed providers dates its prices, so treat all of them as "as published on 8 October 2026" and confirm before you book. Our school directory tracks published course costs across 34 schools, and our audit of which schools teach saturation explains why the closed bell market is so thin.

The cost nobody itemises: crossing over

Almost every article on this topic treats certification as a one-time purchase. It isn't. If you work across markets you will pay a certifying body again, periodically, for the rest of your career — and these fees are published, which makes them the most reliable numbers on this page.

Sources: DCBC Crossover fees; ADAS Fees Overview, updated 4 June 2025. ADAS certificates are issued for five years; ADAS crossover applies only to divers from organisations with reciprocal recognition agreements.

The fees are modest. The paperwork is not. A DCBC crossover wants scans of your diving and training certificates, photo identification, a current workplace first aid, CPR and AED certificate, a current oxygen provider certificate, a current diving medical for most diver grades, a recent passport photograph, and logbook entries — usually covering the past five years, with employer contact details where the logs are unstamped. Supervisor grades add hard experience counts: 200 dive logs as a diver plus 25 supervisory logs in the past five years for Inshore Air Diving Supervisor; at least 50 surface-supplied decompression dives in the past five years, including 25 supervisory and 10 on mixed gas, for Surface Supplied Mixed Gas Supervisor. Several offshore supervisor grades also require the Canadian Regulatory Module exam.

ADAS adds its own trap for HSE holders. Its mutual recognition policy accepts pre-1998 UK HSE certificates as equivalent outright, but for certificates issued after 1998 it requires proof that the holder achieved the bottom times the Australian standard demands — and gives the example that AS 2815 Part 3 requires 30 hours of bottom time over a minimum of twelve weeks. Divers who cannot evidence it may be required to undergo further training. Offshore supervisor crossover applicants must also sit an Australian legislation exam. The policy is internally inconsistent about whether the Executive Director or the Board decides equivalence, which tells you something about how discretionary the process is.

Keeping everything current is a career-long administrative load in its own right; our guide to recertification and ongoing training goes through the renewal cycle in detail.

The medical is a separate gate, and it is annual

No certification scheme will let you dive on the ticket alone. Every one of them requires a current certificate of medical fitness, and the medical is the commonest reason a career ends early.

In Great Britain the certificate must be issued by an Approved Medical Examiner of Divers. HSE approves AMEDs but does not employ them: you or your employer agree the fee with the doctor directly, and HSE publishes no price. You need an initial medical before you start training or assessment, your GP must countersign the questionnaire and may charge for that, and the certificate is valid for a maximum of twelve months, renewed annually with a fitness test. The AMED can restrict the type or depth of diving permitted. If you are failed or restricted, you have 28 days to appeal in writing to HSE. HSE also recognises six classes of practitioner beyond its own list, four of them outside the UK — Netherlands diving doctors, Norwegian approved doctors, Republic of Ireland approved doctors and States of Guernsey doctors, plus Northern Ireland and Ministry of Defence practitioners.

The ADCI standards set a different rhythm. The publicly available sixth edition requires an initial examination for anyone exposed to hyperbaric conditions and sets out a test battery for initial and annual examinations: history and physical, chest X-ray, pulmonary function, audiogram, full blood count, urinalysis and a PPD, with colour blindness tested at the initial only and an EKG required annually from age 35. A pregnancy test is recommended before saturation diving. Re-examination is mandatory after a diving-related injury or illness requiring 72 hours or more in hospital, or after decompression sickness with audio-vestibular or central nervous system involvement, or arterial gas embolism. Records are kept for at least five years after the last hyperbaric exposure. The edition we read is internally inconsistent about whether the annual examination is required or recommended — one section says required, another calls periodic examinations recommended.

On the recurring search for an "ADCI dive physical doctors list": ADCI's standards specify what the examination must contain and who may sign it, not a public roster of named physicians in the way HSE publishes AMEDs. If you need a US examiner, the practical route is to ask the school or contractor who they use, because they will have one. For what the examination covers in detail, see our breakdown of the commercial diving medical certificate.

Sources: HSE, Careers in diving, updated 21 May 2026; HSE, Certificate of medical fitness to dive, updated 21 May 2026; ADCI Consensus Standards, 6th edition, 2011.

Closed bell: the one ticket money cannot buy

Every level up to offshore surface supplied is bought with a course fee. Closed bell is not. It is gated by logged work, and the gate is specific.

The IDRCF's consolidated Closed Bell Diver Training standard, version 1.1, requires that before starting the course you hold a valid, approved surface-supplied qualification to 50 m and have held it for at least twelve months; hold a medical fitness certificate valid for the whole course; hold a first aid at work certificate or complete it during the course without counting that time toward minimum course hours; and have logged, since qualifying as an offshore surface-supplied diver, "at least 100 dives using SSBA" and "at least 100 hours of bottom time". Twenty of those dives must be deeper than 15 metres. Nothing shallower than 6 metres counts. Training dives do not count.

The course itself is about eighteen days for the closed bell competencies, and its minimum content is unusually prescriptive: 29 bell lockouts as diver and 29 as bellman, 14 complete bell runs including transfer under pressure, at least five simulated rescues of an unconscious diver, at least four chamber pressurisations and pre-dive bell checks on four separate days, lockouts at around 55 m, around 70 m and beyond 80 m, and a decompression from a living depth deeper than 50 m. An instructor must be in the bell for at least the first three lockouts.

ADAS applies exactly those numbers to its Part 4 course and to Part 4 crossovers, and will audit logbooks to confirm them. Applicants who cannot evidence the lockouts go to a top-up programme, a recognition-of-prior-learning process, or a case-by-case assessment. ADAS Part 4 is delivered at one establishment, Commercial Dive Academy at Beauty Point in Tasmania; the qualification permits diving to 300 m and the course ends with a saturation dive to about 100 m. DEEP's HSE Closed Bell course in Chepstow runs three weeks for a cohort of six, with the saturation dive and examination in week three, and quotes price on application.

Source: IDRCF, Closed Bell Diver Training, version 1.1, hosted by DCBC; cross-checked against ADAS Closed Bell (Part 4) and DEEP, HSE Closed Bell Diver Course.

Those numbers are the real reason saturation careers are rare rather than the course fee. A hundred offshore dives and a hundred hours of bottom time is years of work for most divers, and the employers who can provide it are few: our audit found that only 17 of 876 companies in the global directory run saturation at all, as set out in who actually runs saturation. The route from an entry-level national ticket to a sat berth is long enough that we mapped it separately in from the Chilean licence to international saturation.

Supervisor certification is a separate system again

Searches for "ADCI diving supervisor requirements" and "ADCI dive supervisor requirements" are among the most common on this topic, and they conceal a split that catches people out: the supervisor ticket and the diver ticket are issued by different bodies in the offshore world, and holding one does not fix a problem with the other.

IMCA issues two supervisor grades, Air Diving Supervisor and Bell Diving Supervisor. An air-qualified supervisor cannot take charge of a bell operation. Candidates must pass an approved preparatory course, log on-the-job development time as a trainee countersigned by the monitoring supervisor, be recommended by their company after satisfactory offshore reports, and pass a written IMCA examination; bell candidates must pass the air examination first. Certification then requires annual CPD to stay valid, and IMCA's December 2024 note is explicit that supervisors must hold in-date CPD status to remain recognised for work with member companies. The minimum panel hours and dive counts live in IMCA D013, revision 5 of June 2024, which IMCA does not publish free.

IMCA recognises three comparable national supervisor certificates: ADAS offshore diving supervisor, DCBC offshore diving supervisor, and NDC-CI offshore diving supervisor at category B4. ADCI's supervisor grades are not among them. ADCI's own requirements, in the publicly available sixth edition of its standards, are expressed as field days and working dives — 200 field days and 50 working dives for Air Diving Supervisor — plus an examination and verifiable endorsements from member companies. The bell and saturation supervisor rows of that matrix were not legible in the public copy we read, so we are not publishing numbers for them.

One sentence in IMCA's Gulf of Mexico information note, IN 1211 of 11 March 2014, is worth memorising. The special arrangements it describes let certain long-serving Gulf supervisors obtain IMCA supervisor certification without the normal route — but the note states that a supervisor certificate issued that way "does not validate the supervisor's diving qualification" where that qualification is not IMCA-recognised. Those arrangements for existing companies were ended at the close of 2014. New applicants must have acted as a bell or air diving supervisor for more than two years, have been with the company six months, complete an approved supervisor course, log panel hours under D013 and pass the examination within two years of nomination.

Life support technicians sit in the same awkward space: IMCA certifies LSTs, and the ADAS Mutual Recognition Table maps only IMCA qualifications onto its own LST certificate, with no HSE, DCBC, Havtil, NDC, French or South African equivalent listed. We describe the role itself in what a life support technician does in saturation.

When a whole country falls off the list

This is the risk no school mentions and no comparison article admits: your certification can stop being recognised abroad through no fault of yours.

It happened to France. At the IDRCF meeting in October 2024 the forum suspended French membership. Havtil, Norway's offshore regulator and an IDRCF member, published its position on 20 January 2025: the IDRCF no longer accepts French diving certificates issued after 14 June 2024; France no longer meets the criteria for mutual recognition; and the database of previously issued French certificates is unavailable, so even older certificates cannot be authenticated. Havtil will not recognise French certificates at Norwegian onshore facilities or on the Norwegian shelf until the French authorities meet the requirements again. Divers whose French certificates had already been verified by a Norwegian employer may continue working, but anyone wanting supervisor or saturation training cannot get it while verification is impossible.

DCBC applied the same decision: no French certifications for direct crossover applications where the training certificate was issued after 14 June 2024. HSE added validity dates to French qualifications in its 1 January 2025 revision, so French certificates appear on the approved list only if issued on or before 14 June 2024. ADAS does the same. IMCA's recommended practice D 088 records that recognition of French Class 2 mention A certificates ceased after that date.

One date, four bodies, one national scheme closed out of the international market. And France is not the only moving part.

Sources: Havtil, Temporary suspension of French diving certificates, 20 January 2025; DCBC, International recognition; HSE List of Approved Diving Qualifications, 1 January 2026, including its table of changes for 2025 and 2026; IMCA D 088, Diving certification and verification, revision 0.2, February 2026.

The South Africa row deserves a second look, because it is the clearest proof that there is no shared recognition standard. HSE lists current South African Class I saturation, Class II surface-supplied mixed gas and air, Class III and Class IV certificates with no date restriction at all. ADAS will not touch anything issued after 30 June 2010. Both positions are published, current, and in direct conflict. Which one applies to you depends entirely on where you are trying to work.

Movement is not always restrictive, either. IMCA's D 088 added recognition of Galician diving certificates in revision 0.1 of January 2026 and Havtil qualifications for surface-supply and closed bell in revision 0.2 of February 2026. The lists change. Check the current edition rather than a blog post, including this one.

What the internet gets wrong about commercial diving certification

"IMCA-approved diver training." There is no such thing, and IMCA said so publicly on 12 June 2025, warning that some schools were advertising it. IMCA does not approve individual diver training schools; certificates issued solely by training schools are not recognised; and IMCA only recognises training with proper oversight. Its acceptance criteria in IN 1385 require that certificates be issued by a national government or government-appointed agency, "not the training facility", and be verifiable. If a school's marketing says "IMCA certified diver", walk away.

"ADCI is the American equivalent of HSE." It is not an equivalent of anything, because HSE is a regulator enforcing statute and ADCI is a non-profit association whose card functions as evidence of employer compliance. OSHA's standard, 1910.410, requires only that each dive team member have the experience or training necessary for their tasks, with first aid and CPR training and, for those exposed to hyperbaric conditions, training in diving physics and physiology. It names no certifying body.

"Get any ticket and top up later." Topping up works inside the HSE–ADAS–DCBC triangle, where the fees are published and the process is documented. It does not work from outside it. Holders of non-IDRCF tickets applying to ADAS go through recognition of prior learning or recognition of formal training rather than crossover, with no published fee and no guaranteed outcome.

"Certification is a one-off cost." ADAS certificates are issued for five years and then need renewing at A$360 to A$600 depending on grade. DCBC requires renewal. IMCA supervisor certification requires annual CPD. The medical is annual. The logbook has to stay current — DCBC wants five years of entries, and unstamped entries need employer contact details, which is a problem if the employer has gone.

"The scheme tells you what the diver can do." It tells you less than you think. Restricted variants of ADAS Parts 2 and 3 omit tool skills, the wet bell and hot water suit, and nothing on the certificate's face says so — HSE has to footnote it. Dry suit and nitrox training are not included in ADAS qualifications unless specified. A Canadian surface-supplied diver may only dive on SCUBA if the reverse of the certificate has been endorsed for it.

"EDTC sets a European standard that everyone follows." The European Diving Technology Committee publishes genuinely influential documents — a competence standard updated March 2018, a fitness to dive standard updated 10 December 2024, guidance on safe working practices issued in 2025, guidance for diving on renewable energy projects — and HSE's criteria for approving non-UK qualifications treat participation in the EDTC or the IDRCF as a condition of approval. But EDTC publishes guidance, not licences. No diver holds an EDTC certificate.

Choosing, for the market you actually want

Work backwards from the employer, not forwards from the course.

North Sea and international offshore. You need a ticket on the IMCA list, which in practice means HSE, ADAS, DCBC, Havtil or NDC at offshore level. In the UK that is HSE SCUBA, then Surface Supplied, then the Surface Supplied (Top-Up) — the Top-Up being the certificate that converts an inshore diver into an offshore one. Budget around £14,750 inclusive of VAT for the ten-week combined route at one approved provider, plus the medical, plus your own kit.

UK inland and inshore. HSE SCUBA alone opens the shellfish, media, scientific and archaeological classes, and is the prerequisite for Surface Supplied. HSE lists twelve recognised assessment organisations, eleven of which offer SCUBA; only two cover the whole air ladder. We look at how this market actually operates in inland commercial diving in the United Kingdom.

United States. Train at an ACDE-accredited school and get the ADCI card, because that is what Gulf employers use. If you want the option of leaving, the ACDE route is the one IMCA recognises, and a DCBC assessment is the practical bridge to the rest of the world — which is why a Seattle school offers exactly that.

Canada. DCBC, because it is written into provincial law in most of the country and required in the offshore. It is also, as the crossover tables show, the most widely accepted single ticket to hold.

Australia, New Zealand and much of Asia. ADAS, which you can obtain at accredited schools in Australia, New Zealand, Singapore, Malaysia, Türkiye or Spain. Note that schools outside Australia may not be able to award the Australian Qualifications Framework certificate even though the ADAS licence is issued at all accredited establishments.

Anywhere you are not sure. Ask the regulator, then ask the contractor, then book the course. Singapore's Workplace Safety and Health Council publishes its own list of acceptable commercial diving certifications, which accepts ADCI alongside HSE, ADAS, DCBC, INPP, Malaysia's CIDB, Norway's regulator and South Africa's Department of Labour — a reminder that national acceptance lists are not copies of each other, and that the one that matters is the one covering the water you will be working in.

Sources

1. HSE — List of Approved Diving Qualifications, issued 1 January 2026, consulted 8 October 2026.
2. HSE — Approved diving qualifications (page updated 25 February 2026), consulted 8 October 2026.
3. HSE — Criteria for approval of non-UK diving qualifications, 9 July 2018, consulted 8 October 2026.
4. HSE — Careers in diving (updated 21 May 2026), consulted 8 October 2026.
5. HSE — Certificate of medical fitness to dive (updated 21 May 2026), consulted 8 October 2026.
6. HSE — Diver competence assessment organisations (updated 26 February 2026), consulted 8 October 2026.
7. HSE — Classes of approved medical practitioner, 24 February 2024, consulted 8 October 2026.
8. legislation.gov.uk — Diving at Work Regulations 1997, regulation 12, consulted 8 October 2026.
9. IMCA — Verify a Diver Training Certificate, consulted 8 October 2026.
10. IMCA — IN 1385, Diver training certificates: IMCA acceptance criteria, 24 March 2023, consulted 8 October 2026.
11. IMCA — IN 1415, ADCI "International Endorsement" diver training certificates: clarification on IMCA recognition, 26 July 2018, consulted 8 October 2026.
12. IMCA — Diving certification, consulted 8 October 2026.
13. IMCA — D 088, Diving certification and verification, revision 0.2, February 2026, consulted 8 October 2026.
14. IMCA — IN 1211, Gulf of Mexico special arrangements for experienced diving supervisors, 11 March 2014, consulted 8 October 2026.
15. IMCA — Warning over rogue diving schools offering non-existent "IMCA approved" in-water diver training, 12 June 2025, consulted 8 October 2026.
16. IMCA — Diving Supervisor certification, consulted 8 October 2026.
17. IMCA — D013, Offshore diving supervisor and life support technician certification schemes, revision 5, June 2024, consulted 8 October 2026.
18. DCBC — Certification, consulted 8 October 2026.
19. DCBC — Crossover, including published fees, consulted 8 October 2026.
20. DCBC — International recognition, consulted 8 October 2026.
21. IDRCF — Closed Bell Diver Training, version 1.1 (hosted by DCBC), consulted 8 October 2026.
22. ADAS — Mutual Recognition Table, version 3.0, 11 December 2024, consulted 8 October 2026.
23. ADAS — Mutual Recognition Policy, version 1.0, consulted 8 October 2026.
24. ADAS — International Equivalents, consulted 8 October 2026.
25. ADAS — Fees Overview (updated 4 June 2025), consulted 8 October 2026.
26. ADAS — Closed Bell (Part 4), consulted 8 October 2026.
27. ADAS — Occupational SCUBA to 30m (Part 1) and accredited training establishments, consulted 8 October 2026.
28. ADAS — Scheme overview, standards and entry requirements, consulted 8 October 2026.
29. ADCI — International Consensus Standards for Commercial Diving and Underwater Operations, 6th edition, 2011 (publicly mirrored copy), consulted 8 October 2026.
30. O*NET OnLine — Certification record: ADCI Air Diver, consulted 8 October 2026.
31. My Next Move — Certification record: ADCI Bell/Saturation Diving Supervisor, consulted 8 October 2026.
32. OSHA — 29 CFR 1910.410, Qualifications of dive team, consulted 8 October 2026.
33. OSHA — Letter of interpretation on commercial diver certification, 29 March 2000 (archived), consulted 8 October 2026.
34. ANSI/ACDE-01-2009 — American National Standard for Divers: Commercial Diver Training, Minimum Standards, consulted 8 October 2026.
35. IDSA — List of Equivalence 2025/2026, July 2025, consulted 8 October 2026.
36. EDTC — Documents, consulted 8 October 2026.
37. Havtil — Temporary suspension of French diving certificates, 20 January 2025, consulted 8 October 2026.
38. Commercial Diver Training Ltd — HSE Air Diver Course, consulted 8 October 2026.
39. Commercial Diver Training Ltd — HSE Surface Supplied Diver, consulted 8 October 2026.
40. Commercial Diver Training Ltd — HSE Professional SCUBA including FAW and O2, consulted 8 October 2026.
41. The Professional Diving Academy — HSE Surface Supplied, consulted 8 October 2026.
42. The Professional Diving Academy — HSE Surface Supplied (Top-Up), consulted 8 October 2026.
43. Divers Institute of Technology — Financial aid and programme costs, consulted 8 October 2026.
44. Divers Institute of Technology — International assessments, consulted 8 October 2026.
45. DiveSafe International — Commercial SCUBA Diver, consulted 8 October 2026.
46. DiveSafe International — Restricted Surface Supply Diver, consulted 8 October 2026.
47. DEEP — HSE Closed Bell Diver Course, consulted 8 October 2026.
48. Justice Laws Canada — Canada–Newfoundland and Labrador Offshore Area Occupational Health and Safety Regulations, SOR/2021-247, s. 172, consulted 8 October 2026.
49. Association of Diving Contractors (UK and Ireland) — Diving schools, consulted 8 October 2026.
50. Workplace Safety and Health Council, Singapore — List of acceptable commercial diving certifications, consulted 8 October 2026.
51. Wikipedia — International Diving Regulators and Certifiers Forum, consulted 8 October 2026.
52. Wikipedia — Association of Diving Contractors International, consulted 8 October 2026.

Frequently asked questions