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Common mistakes when starting out in commercial diving

By Arthur More · professional saturation diver · 18 August 2026

Published 14 July 2026 · 12 min read · 2,314 words

In brief

The costliest mistakes when starting out in commercial diving are picking a school by price or convenience without checking what certification the target market requires, expecting veteran-level pay in the first year, neglecting medical and physical fitness, burning your reputation in a very small industry, and looking for shortcuts to saturation.

Commercial diving is a trade with high barriers to entry and very little tolerance for planning mistakes. A badly chosen course costs thousands of euros and months of time, and you do not get that back. A bad first campaign can close doors on you for years in an industry where everybody knows everybody.

What follows are the mistakes that come up again and again among people starting out. They are not theoretical: they are the ones that turn up systematically in dockside conversations, in hiring interviews and in the CVs companies discard without calling.

1. Choosing a school by price or convenience

This is mistake number one, and the costliest. The beginner's logic is understandable: there is a school two hours from home, it costs less than the alternatives, and the course runs for fewer weeks. They enrol, get the certificate, and discover afterwards that the paper is no use for the job they actually wanted.

The underlying problem is that commercial diving training is regulated country by country, and national schemes are not interchangeable. A national qualification can be perfectly valid for harbour work in that country and worthless for getting a berth on a dive vessel in the North Sea at the same time. That is exactly the case with Spanish commercial diving qualifications: they are valid for working in Spain, but they are not the route into international offshore work.

What to do instead: decide first where you want to work, and work backwards from there. The school is a consequence of that decision, not the starting point. Compare schools by real-world recognition rather than by logistics, in the list of commercial diving schools.

Check whether the school is recognised by the body of the market you are aiming for, not whether it has a good website
Ask in writing exactly which certificate the course issues, with its full official name
Cross-check that name against the public lists of accepted qualifications for that country or scheme
Talk to former students who graduated in the last two years and ask them where they are working now
Be wary of any promise of job placement: no serious school guarantees employment

2. Not finding out which scheme each region requires

Related to the point above, but it deserves its own entry, because the confusion between acronyms is total when you are starting out. HSE, IMCA, ADCI, ADAS, DCBC, INPP are not competing brands of the same product: they are regulatory and industry schemes with different scopes, and every market has its own preferences.

Roughly speaking: HSE is the British regulator's scheme, and its surface route with top up and above is the reference for the North Sea; IMCA is the marine contractors' association, and its recognition works as a de facto passport in international offshore work; ADCI is the North American standard, and its certificates hold outside the United States when they carry the International Endorsement; ADAS is the Australian scheme, with good recognition across Asia-Pacific; DCBC is the Canadian one. Confusing them costs money.

What to do instead: before paying anything, check the official list of the target market to see which certificates they accept. Those lists are public and explicit. We have the practical breakdown in certifications and a direct comparison in HSE, IMCA or ADCI: which certification to choose.

3. Unrealistic salary expectations in the first year

Commercial diving has a reputation for being well paid, and at the top end it is. But the figures circulating online and in videos belong to saturation divers with years of experience and rates from specific markets. Nobody earns that starting out, and anyone who assumes they will is in for a hard knock.

A realistic first year looks more like this: few working days, short contracts, support roles, unpaid waiting time, and expenses that come out of your own pocket, from travel to renewing certificates. Many people quit at this point, not for lack of ability, but because the numbers did not match what they had imagined.

What to do instead: budget the start-up phase as an investment, not as a job. Work out the total cost of training plus twelve months of living on irregular income, and do not start without that cushion. The pay ranges by role and experience are in how much a diver earns, and the full route from scratch in how to become a commercial diver.

4. Neglecting medical fitness and physical condition

Some people spend the course fee before taking a commercial diving medical. That is an absurd gamble: medical fitness is a prior, eliminating condition, and there are findings that rule someone out for good. An exam before enrolling costs a fraction of the course.

The second mistake is treating the check-up as an annual formality that passes itself. It does not. Fitness has to be renewed periodically throughout your career, and losing condition, a respiratory problem, chronic ear infections or excess weight can cost you a campaign you have already been contracted for. What the medical actually assesses is specific and well known, and it is worth knowing before you turn up.

What to do instead: take the medical before spending anything on training, and keep a working level of fitness, not a showcase-gym physique. The trade demands functional strength, the capacity for sustained work in cold and fatigue, and good tolerance for exertion with heavy equipment.

Diving medical before you enrol, not after
Cardiorespiratory endurance work as a foundation, not an add-on
Core and grip strength: the real work is done with tools and against a current
Ear and airway care, the most common cause of avoidable time off
No smoking: it counts against you at the medical and in the water

5. Turning up badly on board and burning your reputation

Commercial diving is a tiny industry. Supervisors know each other, move between companies, and call one another before hiring. Information about a newcomer spreads in days. That means your first campaign is worth far more as a test of attitude than as technical experience.

The classic mistake is turning up with a diver's mindset when what is being asked of you is to be tender: tending gear, hauling on the umbilical, cleaning, staying alert, staying out of the way and learning by watching. Someone who turns up demanding to get in the water, arguing about procedures or checking their phone on deck earns a label that does not come off by changing employer, because it is the same people.

What to do instead: understand that the tender's job is the long interview of your career. Technique can be learned; reliability has to be proven. And that network is also built ashore: staying in touch with old teammates and genuinely getting involved in the community is worth more than a hundred CVs sent out blind.

Be first on deck and last to leave, without making a show of it
Learn everyone's name, including the bridge and engine room crew
Ask when you do not know something: pretending you do is the fastest way to lose the team's trust
Do not argue an order during an operation; if something is not safe, say so with the procedure in hand and at the right moment
Watch how you talk about past employers: everything gets known and everything comes back around

6. Not saving between campaigns

Income in this trade is irregular by definition. You are paid by campaign or by day worked, with dead periods that depend on the market, the weather and luck. The mistake is treating the pay from a good campaign as if it were a monthly salary and adjusting your lifestyle to match it.

The consequences go beyond money. A diver with no cushion takes the first contract that comes along, even with a dubious contractor, on bad terms, or with equipment he is not happy with. Financial pressure is one of the reasons people end up working where they should not.

What to do instead: set aside a minimum fund equivalent to several months' expenses before you allow yourself any upgrade in lifestyle, and always budget for the trade's recurring costs: certificate renewals, the medical, survival courses, travel and insurance. When you can afford to say no, you negotiate far better.

7. Ignoring technical English

The working language of offshore is English, and not conversational English. It is the English of procedures, permits to work, pre-operation briefings, umbilical communications and checklists. A diver who does not understand a supervisor's instruction the first time is a safety risk, and is treated as one.

Many Spanish speakers with good technical training get stuck exactly here. They pass the training, pass the medical, have the right attitude, and never get past local campaigns because they cannot operate safely in an international team.

What to do instead: study the specific vocabulary from day one, not the general kind. Equipment, procedure and emergency terminology, and listening practice with different accents, because on a vessel you will get British, Filipino, South African, Norwegian and Indian crew on the same watch.

Read real procedures and manuals in English, not textbooks
Practise listening with varied accents and background noise, which is the real condition you will face
Learn the standard surface-communication calls and responses by heart
Write your dive logs in English from the start, even if nobody asks you to

8. Looking for shortcuts to saturation

Saturation is the visible, well-paid end of the trade, so it is natural for it to be the goal from day one. The mistake is trying to get there without putting in the road: looking for bell courses without enough surface-supplied diving days behind you, paying for training that promises direct access, or putting yourself forward for positions you have neither the hours nor the references for.

In practice, almost nobody gets into saturation without having worked first as a tender and as a surface diver for a long period, and without someone on the inside vouching for them. Contractors do not put someone in a bell they have not seen work. It is not closed-shop thinking, it is risk management: in saturation, a lapse in judgement cannot be fixed by going back up to the surface.

What to do instead: accept that progress is measured in logged working days and in people who will vouch for you. Build up dives wherever you can, including coastal and harbour work, keep your logbook spotless, and follow the real job listings in empleo. If you are at the starting point, the specific guide is how to get started in commercial diving with no experience.

In short: almost all of these mistakes share the same root, which is making expensive decisions with incomplete information and no patience. The trade rewards the opposite. Researching before paying, budgeting with a margin, looking after your health, behaving well on board and racking up days. Someone who does that for three or four years ends up where they want to be; someone who looks for the shortcut usually ends up out of it.

Frequently asked questions

What is the costliest mistake when starting out in commercial diving?

Choosing the school before deciding on the market. Training is regulated country by country, and the schemes are not interchangeable: a certificate valid for national harbour work may not be enough to get a berth in international offshore work. Decide first where you want to work, check which certificates that market accepts, and choose the school accordingly.

Is a Spanish commercial diving qualification enough to work offshore?

For working in Spain, yes — it is the legally required qualification. For international offshore work, the usual practice is that contractors ask for certifications recognised within the IMCA framework, such as the HSE route, ADAS, DCBC or ADCI with international endorsement. Many Spanish divers end up taking a second, recognised qualification so they can get berths abroad.

How long does it take to get into saturation starting from scratch?

There is no fixed timeframe, but it is rarely less than several years. The normal path runs through working as a tender, building up days as a surface diver, earning references within a contractor, and only then getting access to bell training. Contractors do not bring someone into saturation whom they have not seen work before.

Should I take the medical before or after the course?

Before, always. Medical fitness is a prior, eliminating requirement, and there are conditions that rule someone out for good. Paying for a full course without knowing whether you will pass the medical is taking on an unnecessary financial risk, when the exam costs a small fraction of the training and is settled quickly.

How much English do you need to work offshore?

Enough to understand written procedures, take part in pre-operation briefings, and communicate with the surface without ambiguity. It is not a matter of image, it is a matter of safety: a misunderstood instruction in the water is an incident. It is worth studying technical terminology and practising listening with different accents and background noise.

Published 18 August 2026 · By Arthur More, professional saturation diver

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