We checked 34 diving schools for underwater welding. Two name the standard.

Eighteen schools teach it. Two tell you to what standard.

"Underwater welding" is probably the most over-marketed phrase in commercial diving. It is the hook on half the dive school adverts on the internet, and it is the reason a lot of people find this trade in the first place. So we did the obvious thing nobody seems to do: we opened all 34 school websites in our directory and read what they actually publish about welding.

Thirty-one sites answered. Eighteen of them publish underwater welding training in some form — a course, a module inside a course, or a named specialism. Thirteen publish nothing about it. That part is roughly what you would expect.

The interesting number is the next one. Of those 18, exactly two name the welding standard: BC-opleidingen in Enkhuizen, and The Ocean Corporation in Houston. Two more name a welding or inspection body without naming an underwater code — Atlantic Commercial Diving Centre in Prince Edward Island offers a CWB course (that is the Canadian Welding Bureau, topside), and SEADOG in South Africa lists "Coded Welder" and CSWIP as career destinations rather than as things it certifies.

Everyone else writes some version of "underwater welding and cutting" and stops there.

Why the code matters more than the course

Here is the part the marketing skips. There are three separate things that get approved in underwater welding, and they belong to three different owners.

The weld. In the American system that is AWS D3.6M:2017, Underwater Welding Code — the current edition. It sets three classes: Class A, comparable to conventional surface welds; Class B, for less critical work where lower ductility and moderate porosity are tolerable; and Class O, which must meet another designated code as well as D3.6's extra underwater requirements. Crucially, you do not pick the class. As the underwater repair contractor Subsea Global Solutions puts it, "the selection of the class of weld to be provided is to be determined by the customer or regulatory body."

The procedure. Water depth is an essential variable in a welding procedure specification, so a procedure qualified at 6 m is not automatically good at 30 m. This is the part of the system that just changed: ISO 15614-9:2025, "Specification and qualification of welding procedures for metallic materials — Welding procedure test — Part 9: Underwater hyperbaric wet welding", was published on 5 November 2025 as a first edition, from ISO/TC 44/SC 15 (Underwater welding). It covers processes 111 (manual metal arc) and 114 (self-shielded tubular-cored arc) on steels in ISO 15608 groups 1, 2, 3 and 8, and it defines quality levels A, B and Z — deliberately not the same letters as AWS's A, B and O. For dry hyperbaric work the equivalent is ISO 15614-10.

The welder. That is ISO 15618-1:2016, "Qualification testing of welders for underwater welding — Part 1: Hyperbaric wet welding", with ISO 15618-2 covering dry hyperbaric. This is the piece of paper with your name on it, and it is the one a contractor asks for. It is also the one that expires and has to be maintained.

A school certificate is a fourth thing entirely, and it is not on that list. It says you attended. Whether you can then weld to Class A on someone's FPSO is settled by the procedure and by your welder qualification, usually re-tested against the job's own specification.

The two schools that name a code

BC-opleidingen and the Hyperbaric Welding Center, Enkhuizen (Netherlands)

This is the most transparent underwater welding offer in the directory by a distance, and it is not close. BC-opleidingen — ISO 9001 certified and an IMCA member — runs the Hyperbaric Welding Center as a joint venture with the Lasinstituut, the Dutch welding institute. In their own words, the two organisations set it up "driven by a shared ambition to breathe new life into the training pathway for underwater welders" and to close "a gap in the current Dutch (and European) range of training courses".

What they publish is a three-part offer rather than a course: training underwater welders "from various starting points and at different levels"; organising welder qualifications under both European and American standards; and running renewal days to keep those qualifications valid. The qualification is to EN ISO 15618-1 or AWS D3.6M, with other standards on request. Tests are carried out under DNV oversight, with the Lasinstituut acting as an authorised DNV examiner, and DNV — not the school — taking the certification decision and issuing the certificate. Two tracks are listed, a five-day qualification route and an eleven-day extended route, taught in English and Dutch. Training is at the BCO centre in Enkhuizen, on the Markermeer, with indoor and outdoor dive locations.

That separation — school trains, independent body certifies — is the whole point, and it is exactly what the rest of the market leaves vague.

The Ocean Corporation, Houston (United States)

Ocean Corp, in business since 1969 and with more than 15,000 alumni, names AWS D3.6M on its commercial diving certification page, where underwater welding and cutting sit alongside advanced mixed-gas, bell and saturation diving. It is one line rather than a published qualification pathway, but it is one line more than 16 other schools give you.

Four schools give welding a page of its own

A dedicated page is a weak proxy for seriousness, but it is a proxy. Four schools have one.

BC-opleidingen (Netherlands) — covered above. Divers Institute of Technology in Seattle, where "Welding & Underwater Welding" is course 4 of the seven-course programme and the page states it covers topside welding skills, underwater welding, and underwater cutting and burning. Norsk Yrkesdykkerskole at Fagerstrand in Norway, which runs Underwater welder as a standalone course with published intakes — the next one listed is 16–27 November 2026. And the Underwater Training Centre – SA in Australia, whose page is not a course page at all but an explainer, and an unusually honest one.

Thirteen schools publish nothing — including all three British ones

Thirteen of the 31 reachable schools publish no underwater welding content at all. The geography is the surprise: all three United Kingdom schools in the directory — Commercial Diver Training Ltd and Interdive Services, both in Plymouth, and Professional Diving Academy at Dunoon — publish nothing about welding. So do two of the three South African schools, three of the six Canadian, three of the Spanish seven and KBA Training Centre in Singapore.

That is not evidence that nobody welds in Britain. It is evidence about how the HSE-approved training market is structured: the UK schools sell the qualification that gets you onto a worksite, and coded welding is treated as a separate ticket bought separately. Which is, as it happens, the correct way round.

The only programme with a classification society behind it

There is one more route that does not show up in a school audit, because the school is not the one issuing anything: Weldcraft-Pro, run by the welding engineer David J. Keats from York.

Weldcraft-Pro licenses an 80-hour underwater welding programme — 40 hours dry, 40 hours wet, nine learning outcomes — which approved centres deliver with their own instructors. It follows European Welding Federation document 570-01 for fillet welder on plate, with welder-divers coded to ISO 15618-1, AWS D3.6M and/or BS 4872-1. Weldcraft-Pro states that the programme is approved by the ABS Maritime Academy and that the certificate of verified achievement is issued by EAL, which makes it, in the company's words, "the only class society (ABS) approved underwater welding programme available". It is also recognised by the CPD board of IMarEST.

Two clarifications, because they are the sort of thing that gets lost in a marketing line and we would rather state them than let a reader assume.

First, what a class society certifies here. ABS runs a Certification of Maritime Training programme, which is "an independent third-party review and assessment of the facilities, courses and instructors" at a training provider, aligned to STCW and run as a quality-system audit. We could not confirm from public sources which ABS scheme the Weldcraft-Pro approval sits under. Either way, a class society certifying a training provider is a different thing from a class society approving your weld on a specific job — and the second is what gets paid for.

Second, the awarding body. EAL is a specialist engineering and manufacturing awarding organisation and end-point assessment organisation, now part of the Enginuity Group; Weldcraft-Pro's page still describes it as part of SEMTA, which was Enginuity's former identity. The award itself is the substantive point: the certificate comes from an external awarding organisation rather than from the school that taught you, which is exactly the separation the rest of this market lacks.

Weldcraft-Pro lists approved centres in seven countries. Five are currently running courses — DiveWise Tec in Belgium, YRGO in Sweden, Marex Subsea Welds in Greece, MM Matrix Integrity in Malaysia and Norsk Yrkesdykkerskole in Norway — and four are listed as approved but not currently running: Arc Subsea in Australia, ABJ Welding in South Africa, Commercial Diving Academy in Florida, and Professional Diving Academy in Scotland.

Three of those nine are schools in our own directory. And the overlap explains one of our "publishes nothing" results: Professional Diving Academy is an approved Weldcraft-Pro centre that is not currently running the course, so its silence on welding is consistent rather than contradictory. NYD, which is running it, does publish a welding course. The system checks out.

What our own directory got wrong

We will take the hit on this one, because the audit caught us as well as everyone else.

Satdiver's school profiles carry a one-line "what it trains" summary. Measured against what the schools actually publish, that summary understated welding at six schools: Norsk Yrkesdykkerskole, The Ocean Corporation, Underwater Training Centre – SA, Commercial Dive Academy, Omne Marine and Commercial Diving Institute of Canada all publish welding training that our summary did not mention. NYD was the worst of them — a school with a standalone underwater welder course and published intake dates, summarised by us without the word "welding" in it.

That is the failure mode of any curated directory: a summary written once from a homepage goes stale, and the error is invisible until somebody re-reads all 34 sites. We are correcting the affected profiles. The lesson we would pass on to anyone using a directory — ours included — is that the school's own site is the primary source and a directory is an index to it.

What to ask a school before you pay

If underwater welding is the reason you are considering a diving school, these are the questions that separate a real offer from a bullet point. They are the questions this audit was effectively asking on your behalf.

• To which standard is the welder qualification issued — ISO 15618-1, AWS D3.6M, BS 4872-1, something else? If the answer is "our own certificate", that is the answer.
• Who issues it? The school, or an independent body — a class society, a welding institute, an awarding organisation? Who takes the certification decision matters more than who taught the course.
• To what depth and in what position was the test done, and what does that let you weld afterwards? Depth is an essential variable.
• How long is it valid and how is it renewed? A qualification with no renewal path is a souvenir.
• How many hours are actually wet? Weldcraft-Pro's programme splits 40 dry and 40 wet, which is a usable yardstick for comparison.
• Will an employer in the market I want to work in accept it? Ask the employer, not the school.

And one piece of context from the audit that is worth holding onto: the diving comes first. Every route here assumes you are a commercial diver who welds, not a welder who dives. If you are at the start of this, read how to become an underwater welder and how to train as a commercial diver before you choose a school, and what underwater welding actually pays before you choose a loan.

One more thing nobody mentions: the electricity

Welding underwater means putting a few hundred amps of DC into the water next to a human being. The governing industry document is IMCA D 045, "Code of practice for the safe use of electricity under water", first published in October 2010 and now at revision 1.1 of May 2024, with revision 1 adding a section on diving near high-power cables. It covers electric shock risk to divers, toxic emissions from insulation and ignition risk from electrical faults, across subsea equipment, cables, diving suits, ROVs and habitats.

In practice that means a safety switch between the power source and the diver, so the surface can isolate current and voltage on command. Equipment designed for the job — such as the 400 A DC monitor and control switches sold by Weldcraft-Pro — cites D 045 directly. If you are being taught to weld underwater and nobody has explained the switch, the course is not a welding course.

The full table: all 34 schools

Every school in satdiver's directory, as its own website read on 1 November 2026. "Own page" means a URL dedicated to underwater welding rather than a mention inside a course list.

How we counted this

On 1 November 2026 we requested the homepage of all 34 commercial diving schools in satdiver's directory and then followed up to twelve internal links per site whose URL suggested a course, programme, training or welding page, reading the text of each. Thirty-one sites returned a readable page. Three did not respond within the audit window: CDA Technical Institute in Jacksonville, IGAFA in Galicia and Océanos in Barcelona. They are shown in the table as "site did not respond", not as "no welding" — CDA Technical Institute in particular trades at commercialdivingacademy.com and is very likely the Florida centre Weldcraft-Pro lists as "Commercial Diving Academy", so treat its blank row as missing data rather than evidence.

A school is recorded as publishing underwater welding when its own site describes welding training, a welding module inside a course, or a named welding specialism, in English, Spanish, French or Dutch. We counted Commercial Diving Institute of Canada on the strength of its named "Hydro-tech Welding" advanced programme. We excluded matches that were not underwater welding: IFP Tenerife's host site lists a general "iniciación a la soldadura" short course in an agricultural training catalogue, which is not the same thing, and several Spanish-language pages produced false matches on the ordinary word las. Every positive in the table was read in context before it was counted.

"Standards or bodies named" records a welding code or certifying body appearing anywhere we read on the site. It is a floor, not a ceiling: a school may qualify welders to ISO 15618-1 and simply not say so online, and a school may name a code on a page we did not reach. Twelve pages per site is a sample, not a census, and a site that buries its welding page five clicks down will be undercounted here. The direction of that error is one way — we will have missed welding offers, not invented them.

Finally, this measures publishing, not capability or quality. It cannot tell you whether a course is any good, whether the qualification is accepted by the employer you want, or whether a school that says nothing online will qualify you properly if you ring and ask. What it does measure is how much a prospective student can find out before they pay, and on that the answer is: at 29 of 31 schools, not enough to know what you are buying.

Frequently asked questions

Sources

Everything above is either our own count or a named primary source, read on 1 November 2026.

• The 34 school websites listed in the table, read directly. satdiver's commercial diving school directory.
• American Welding Society — D3.6M:2017 Underwater Welding Code (classes A, B and O; 2010 and 1999 editions listed as historical).
• ISO — ISO 15614-9:2025, published 5 November 2025, edition 1, ISO/TC 44/SC 15.
• ISO 15618-1:2016, Qualification testing of welders for underwater welding — Part 1: Hyperbaric wet welding; ISO 15618-2 and ISO 15614-10 for dry hyperbaric work.
• IMCA — IMCA D 045 / R 015, Code of practice for the safe use of electricity under water, rev. 1.1, May 2024 (originally October 2010).
• Hyperbaric Welding Center (BC-opleidingen and Lasinstituut) — standards and certification routes, and the BC-opleidingen underwater welding course page.
• Subsea Global Solutions — Underwater weld repairs: requirements and execution, on weld classes, essential variables and class-society approval in practice.
• American Bureau of Shipping — Certification of Maritime Training.
• Enginuity — EAL, part of Enginuity Group.
• Weldcraft-Pro's published programme, products and approved-centre list — summarised in our Weldcraft-Pro listing.

Keep reading

The companion pieces to this one: how to become an underwater welder for the route, underwater welding pay and training costs for the money, wet versus hyperbaric dry welding for the technique, and five of 34 schools teach saturation diving for the same directory counted a different way. The school directory itself holds all 34 profiles, and equipment suppliers covers the consumables and safety gear side.