English is the working language of international offshore diving, and it acts as a real hiring filter. You don't need a high academic level, but you do need to understand and be understood over the radio under pressure, follow safety briefings and permits to work, and write basic reports accurately.
A lot gets said about certifications, physical fitness and coping with confinement. Not much gets said about the barrier that keeps the most Spanish-speaking hopefuls out of international offshore work: the language. It isn't a formal requirement in most cases, and that's exactly why it catches so many people off guard.
In a diving operation, communicating badly isn't an inconvenience: it's a risk. And companies know it.
Why English is the sector's language
The crew of a dive support vessel is international by definition: the supervisor might be British, the DP operator Norwegian, the divers from half a dozen nationalities and the crew from yet another. With that mix, a common language is needed, and in the maritime and offshore world that language is English.
So is the documentation. Operating procedures, the sector's codes of practice, equipment manuals, permits to work, risk assessments and inspection forms are all written in English, even on operations carried out in non-English-speaking countries. The standards we describe in this article about IMCA are a good example.
Where it's actually used
Communication with surface
This is the critical use. The diver talks to the supervisor over an audio channel, sometimes with background noise and with the voice distorted by helium and corrected by a processor. There's no room there for elaborate sentences: short, standardised, repetitive phrases are used, and what's understood is confirmed by repeating it back.
What's needed is precise and limited: numbers, directions, tools, statuses, confirmations and warnings. A narrow vocabulary, mastered perfectly, is worth far more than broad but hesitant English.
Pre-job briefings
Before every operation there's a briefing where the task, the risks, the limits and who's responsible for what are explained. Missing something there is dangerous, because that's when you learn what's going to be done and what's off limits. It's also the moment to ask questions, which takes a minimum level of fluency.
The paperwork
Dive logs, work reports, inspection reports, incident notifications. The writing doesn't need to be elegant, but it does need to be clear and unambiguous. In inspection work, moreover, the report is the final product of the job, as we explain in underwater inspection diver.
Living together
Weeks spent living alongside people you can't talk to take their toll, especially inside a saturation chamber, where isolation is already at its peak on its own, as we describe in life inside the chamber. Language also determines whether you're part of the team or left on the sidelines.
What level you need
The practical answer: enough to work safely, not enough to pass an academic exam. Translated into concrete abilities, a diver should be able to understand spoken instructions with varied accents and background noise; respond briefly and without hesitation; take part in a safety briefing and ask questions; read a procedure and identify its limits and prohibitions; and write an understandable work report.
Accents deserve attention of their own. Offshore work brings together Scottish, Norwegian, Filipino, Indian, South African English and many others. Getting your ear used to that variety matters as much as expanding vocabulary, and it's the part a conventional language school trains worst.
If the goal is training abroad, bear in mind that most of the leading commercial diving courses are taught in English and some schools ask you to prove a minimum level. The schools are listed in commercial diving schools, and the general pathway in how to become a commercial diver.
How to prepare for it sensibly
Start with the vocabulary of the trade, not general vocabulary. Tools, equipment parts, types of structure, action and state verbs, units and numbers. Your own glossary of two or three hundred words, properly mastered, covers most of a working day.
Train your ear with real material: videos of operations, interviews with people in the sector, recordings of communications. It's worth checking out the channels we recommend in who to follow in commercial diving, because the register they use is exactly what you'll find on board.
Practise speaking in short sentences. The temptation to build long sentences works against you: over the radio, brevity and confirmation are what count. Repeating back what you've been told to check you've understood it is standard technique, not a sign of clumsiness.
Read real documentation from the sector: procedures, best-practice guides, public incident reports. It's repetitive, formulaic English that's learned quickly and shows up everywhere, including in what you'll see when preparing for the certifications.
And if you get the chance, look for situations that force you to use it under time pressure. The real breakthrough isn't knowing more words, it's being able to use them when you're uncomfortable, tired or wet.
A realistic note
There are markets where you can work with less English, especially in port works and inland diving within your own country, an area we compare in interior frente a offshore. It's a perfectly respectable way to get started and build up hours.
But the international saturation circuit, where the highest rates described in how much a diver earnsare found, runs in English from start to finish. Investing in the language before investing in the expensive course is usually the most worthwhile decision a Spanish-speaking hopeful can make.
Standardised communications
It's worth understanding that communication in a diving operation isn't free conversation, it's a protocol. Who you're speaking to is identified, a short message is sent, and the receiver confirms by repeating back the essentials. When something hasn't been understood, a repeat is explicitly requested rather than assumed.
That format exists precisely because the channel is poor, the noise is high and the consequences of a misunderstanding are serious. For a non-native speaker, that's good news: it reduces the conversation to a limited set of set phrases that can be learned and practised until they become automatic.
There's another important detail: the supervisor keeps up regular communication with the diver, and answering clearly and normally is part of how the diver's condition is monitored. A confused answer is read as a warning sign, not as a language problem. That's why it's worth answering little but well rather than attempting complicated sentences.
Common language mistakes
The first is pretending you've understood. In a normal work setting that's a bad habit; underwater it's dangerous. Asking for a repeat is built into the protocol and nobody penalises it.
The second is neglecting numbers. Depths, pressures, measurements, codes and times are transmitted constantly, and mixing up figures in another language is easier than it seems. Practising numbers and units out loud until they come out automatically is one of the most worthwhile investments you can make.
The third is sticking to textbook English and never getting used to real spoken English, with accents, abbreviations and sector jargon. That's the difference between passing an exam and understanding a Scottish supervisor through a crackling speaker.
Frequently asked questions
Is English compulsory to become a commercial diver?
Not always explicitly, but in practice it's essential for international offshore work. Crews are multinational, technical documentation is in English, and communication with surface during the dive is a safety element.
What level of English do offshore diving companies ask for?
A specific qualification is rarely required. What's valued is functional ability: understanding radio instructions with noise and varied accents, answering briefly, following a safety briefing, reading procedures and writing clear work reports.
What English vocabulary does a diver need?
The vocabulary of the trade: tools, equipment components, types of structure, action and state verbs, units, numbers, directions and the standard radio confirmation phrases. A narrow, well-mastered glossary pays off more than a broad, shaky vocabulary.
Are commercial diving courses taught in English?
Leading international schools teach in English, and some ask you to prove a minimum level of comprehension. In Spain and Latin America there are programmes in Spanish, but the international circuit runs in English.
How do you train your English for offshore work?
By prioritising technical vocabulary, getting your ear used to varied accents with real sector material, practising short sentences and confirmations the way they're used over the radio, and reading genuine operating documentation, which is repetitive and quick to learn.
Can you work as a commercial diver without English?
Yes, in local markets: port works, inland diving or domestic projects where the working language is your own. It's a valid way to start out, but it limits access to the international saturation circuit, where the best conditions are found.
Published 22 August 2026 · By Arthur More, professional saturation diver
Photo: Ellysia Oldsen · CC BY via Openverse