IMCA is the International Marine Contractors Association, the international association of marine contractors. It isn't a regulator or a school: it's an organisation of companies that publishes the industry's codes of practice and certifies supervisors and life support technicians. Its weight comes from the fact that its members are the ones doing the hiring.
If you start looking at offshore diving job ads, those four letters show up in almost all of them. And yet there's a fair amount of confusion about exactly what this organisation is. It's sometimes called "the IMCA certification", as if it were a diving qualification equivalent to the national schemes, and it isn't.
Understanding exactly what it does and doesn't do saves you wasting time and money.
What IMCA is
The International Marine Contractors Association is an international association that brings together companies in the offshore marine sector: diving contractors, underwater vehicle operators, marine installation and construction contractors, dynamic positioning contractors and marine survey contractors, plus associated suppliers.
In other words, it's an organisation of companies, not of workers or governments. Its members are the companies that run the projects, and its main function is to agree among themselves how things should be done properly, and publish it.
That distinction explains almost everything else. IMCA has no legal authority over anyone. It can't fine anyone, it can't shut down an operation, it doesn't legislate. Its power is of a different kind: it's the power of a group of clients and contractors who have agreed a standard and require it to be met under their contracts.
What IMCA produces
Codes of practice and guidance documents
This is its most important output. IMCA publishes recommended practice documents covering everything from the minimum composition of a diving team to emergency procedures, saturation system maintenance, managing dynamic positioning during diving operations, or bell equipment requirements.
Many of these documents have become the de facto standard for international offshore diving, and in some jurisdictions they're cited as a reference for good practice even without having any regulatory status.
Competence certification for certain roles
IMCA maintains certification schemes for specific positions: diving supervisors, with separate levels for surface and bell diving, and life support technicians, with technician and supervisor levels. These schemes combine training, documented experience and assessment.
Safety flashes
IMCA collects and shares incident and near-miss reports among its members, anonymised. It's one of the organisation's least visible and most valuable contributions, because it means a failure on a vessel in Asia can turn into a change of procedure in the North Sea.
Member auditing
Membership of the association involves meeting criteria and going through verification processes. For a client, hiring an IMCA member is a quick way to screen contractors.
What IMCA does NOT do
This is where the most widespread confusion lies, and it's worth being blunt about it:
IMCA does not train or certify the entry-level diver. There's no such thing as an "IMCA commercial diving course". A diver's initial qualification is issued by national and regional schemes: British, Norwegian, American, Canadian, Australian and others. If someone offers you a diving course "certified by IMCA", be sceptical.
IMCA is not a regulator. The workplace safety legislation that applies to an operation is set by the state in whose waters, or under whose flag, the work takes place.
IMCA does not give you a job. It's not a job board or an agency.
What it does do is recognise certain national certifications as acceptable for working on its members' operations, publishing equivalence criteria. That's the practical link between your certificate and the offshore market. I cover this in HSE, IMCA, ADCI: which certification to choose.
How it affects your employability
In four concrete ways:
It determines which diving certificate is any use to you. If your goal is international offshore work, you need a qualification that's among those the member contractors recognise. Training under a scheme that doesn't fit shuts you out of that market, however good the course is. Check this before paying for enrolment: see schools y certifications.
It sets the ceiling on your progression. To run operations you need the scheme's supervisor certification, and that shapes your whole career planning: logged lock-out hours, specific training, assessment. It's explained in how you progress from diver to supervisor.
It defines how the work is done. The procedures you'll follow on board, the composition of the team, who can stop the operation and what gets drilled in the emergency exercises come largely from these documents. Knowing them makes you a better professional, and it shows in an interview.
It's a signal about the employer. A contractor being a member guarantees nothing on its own, but it is an indicator. A company that isn't in the association and that also operates in international offshore diving deserves more questions. The list of contractors is in the company directory.
The documents that will affect you most
Without going into specific references, which change with revisions, it's worth knowing what areas the industry documentation covers, because it literally describes your day-to-day on board.
Diving team composition and competence. How many people are needed for an operation, what role each one has, and what qualification is required of them. This is what stops a contractor cutting the crew below a safe level.
Systems and equipment. Requirements for bells, saturation systems, umbilicals, gas panels, treatment chambers and hyperbaric evacuation systems, along with their inspection and testing regimes.
Operations. How a dive is planned, how the risk from pressure differential is managed, how diving is coordinated with a vessel on dynamic positioning, what's done in current or poor visibility.
Emergencias. Scenarios that have to be planned for and drilled: diver in distress, loss of gas, loss of bell, abandoning the vessel with personnel under pressure.
Medical fitness and personnel. Medical assessment criteria, fatigue management and working hours.
How to use this in practice
Three concrete pieces of advice for someone building their career.
Before enrolling at a school, check that the qualification you're going to get fits the framework accepted by the contractors in the market you're aiming for. It's the decision with the biggest impact and the easiest one to get wrong. Check against certifications and against schools.
In an interview, showing that you know the principles behind the codes of practice — not from memory, but understanding why they exist — sets you apart immediately from someone who only brings the certificate. It's especially true when you're going for your first offshore position, as I explain in how to land your first job.
And when you're weighing up an employer, treat their membership of the association as one signal among several: incident history, condition of the equipment, stop-work policy and what the people who've worked there say. No set of letters replaces that check.
The reasonable criticisms
In fairness, these are worth mentioning. The main one is structural: it's an association of companies setting the standards applied to their own workers, with no worker representation in the process. Those who make this criticism point out that in a conflict between operating cost and technical requirements, the natural bias of an organisation like this isn't neutral.
The second is about access: a large part of the documentation is aimed at members, which makes it harder for an individual diver to consult directly the standard that applies to them.
The third is about overlap: in markets with strong state regulation, the coexistence of the public rule and the association's standard creates grey areas over which one prevails.
That said, it's hard to argue that the existence of a common standard and a mechanism for sharing incidents hasn't helped make offshore diving far safer today than it was four decades ago. The accidents that drove that change are covered in the article on the real risks of saturation diving.
What to take away
IMCA is the club of the companies that are going to hire you, and that club has written the rules of the game. It doesn't train you, it doesn't employ you and it doesn't regulate you, but it shapes which certificate you need, how you'll work on board and how far you can go. That's why, even though it isn't a diver certification, it's probably the most relevant set of letters in your career if you're aiming at international offshore work.
Frequently asked questions
What does IMCA mean?
IMCA stands for International Marine Contractors Association, the international association of marine contractors. It brings together companies in the offshore sector: diving contractors, underwater vehicle operators, marine installation and construction companies, dynamic positioning contractors and marine survey contractors, plus associated suppliers. It's an organisation of companies, not of workers or governments.
Is there an IMCA commercial diving course or certificate?
No. IMCA does not train or certify the entry-level diver. The initial qualification is issued by national and regional schemes, such as the British, Norwegian, American, Canadian or Australian ones. If someone offers a commercial diving course certified by IMCA, you should be sceptical. What the association does do is publish equivalence criteria between national certifications.
What does IMCA certify, then?
It maintains competence certification schemes for specific roles: diving supervisors, with separate levels for surface and bell operations, and life support technicians, with technician and supervisor levels. These schemes combine training, documented experience in hours and assessment, and they're what the contractors in the international offshore market require.
Is IMCA a regulatory body?
No. It has no legal authority: it doesn't legislate, it doesn't fine anyone and it can't halt an operation. The applicable regulations are set by the state in whose waters, or under whose flag, the work takes place. IMCA's weight is contractual and reputational, because its members are the companies that hire and that require compliance with their codes of practice in their contracts.
How does IMCA affect my employability as a diver?
In four ways: it determines which diving certification is useful for international offshore work, it sets the ceiling on progression because supervising requires its certificate, it defines the procedures you'll follow on board, and it serves as an indicator when assessing an employer. It's worth checking the compatibility of a training scheme before paying for a course.
Published 21 August 2026 · By Arthur More, professional saturation diver
Photo: PiktourUK · CC BY via Openverse
This article is part of our in-depth guide to commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC — the complete picture, with sources.
This article is part of our in-depth guide to commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC — the complete picture, with sources.
This article is part of our in-depth guide to commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC — the complete picture, with sources.
This article is part of our in-depth guide to commercial diving certification: HSE, IMCA, ADCI, ADAS and DCBC — the complete picture, with sources.