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Mines in the Water: What Everyone Should Know About Munitions at Sea

A twenty-minute public awareness programme on sea mines and other munitions left on the seabed. In four short lessons it explains how the legacy arose, who encounters it in everyday life, what to do in the first two minutes after a find, and how journalists and NGOs can cover the subject without putting people at risk. The course deliberately teaches no identification, handling or disposal: the public message is distance, position, report, warn.

Lesson 1

1.1 1. A Century of Metal on the Seabed

MARSAFEMARSAFESea Safety
Public Awareness
Lesson 1

A Century of Metal on the Seabed

Millions of tonnes of munitions were laid, dropped, dumped or lost at sea during the twentieth century. Much of it is still there.

The legacy

How it got there

Sea mines were laid to defend harbours and block shipping. Bombs and shells missed their targets or went down with vessels and aircraft. After both world wars, huge quantities of surplus and captured ammunition — including chemical weapons — were loaded onto barges and dumped offshore because there was no other way to get rid of them quickly. None of this was designed to be recovered later.

Now

Why it has not gone away

Seawater corrodes metal casings slowly. Decades on, many items are buried in sediment, hidden under marine growth, or partly broken open. Storms, currents, trawling and dredging can uncover them or move them. Age makes an item less predictable, not safer — corrosion can expose the contents and damage whatever kept it stable.

Scale

Where it turns up

Baltic and North Sea dumping grounds, Adriatic and Mediterranean coastal waters, the Black Sea, harbour approaches, former front lines and training ranges. Fishermen bring items up in nets. Beachgoers find things washed ashore after storms. Construction crews meet them while dredging or laying cable.

Remember this

This is a live legacy, not a history topic. The metal is still on the seabed, and time has made it less predictable rather than safer.

MARSAFE · Public awarenessLesson 1 of 4

Practical Exercise

Spend fifteen minutes finding out which authority in your country receives reports of suspected munitions found at sea or on the shore. Write down the name and the number. Do not search for locations of specific items or dumping sites.

Summary

Twentieth-century conflict left mines, bombs, shells and dumped chemical munitions across coastal and offshore waters. Corrosion and seabed movement keep the risk current.

Resources for this lesson

Web link

Lesson content: 1.1 1. A Century of Metal on the Seabed

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Lesson 2

1.2 2. Who Meets the Risk, and How

MARSAFEMARSAFESea Safety
Public Awareness
Lesson 2

Who Meets the Risk, and How

Most encounters are accidental and involve ordinary people going about their work or leisure. Knowing the everyday pathways is what makes awareness useful.

People

The everyday encounters

Fishing crews snagging items in nets or dredges. Divers and snorkellers coming across something on a wreck site. Beach walkers finding an object after a storm. Scrap collectors deliberately looking for metal — the highest-risk group of all. Port, cable and offshore construction crews disturbing the bed.

Environment

The slower harm

Corroding casings leak explosive compounds and, in dumped chemical munitions, warfare agents into sediment and water. Contamination can reach marine life and, in some documented cases, fishing catches. Clearance itself carries environmental cost: underwater detonation produces pressure waves and noise that harm marine mammals and fish, which is why specialists increasingly weigh lower-impact alternatives.

Communities

The development cost

Uncertainty holds back harbours, marinas, aquaculture, offshore wind and cable projects, especially in post-conflict coastal economies. Surveying and clearing seabed hazards is often the step that lets legitimate investment and jobs arrive — the safety case and the development case are the same case.

Remember this

The people most likely to encounter underwater munitions are civilians at work or at leisure. Awareness has to travel to them, in language they use.

MARSAFE · Public awarenessLesson 2 of 4

Practical Exercise

Pick one at-risk group in your area. Draft a sixty-second spoken safety message for them in plain language, built around the four response steps. Avoid any description of what objects look like.

Summary

Fishing crews, divers, beach users, scrap collectors and marine construction workers carry most of the exposure, alongside environmental contamination and blocked coastal development.

Resources for this lesson

Web link

Lesson content: 1.2 2. Who Meets the Risk, and How

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Lesson 3

1.3 3. If You Find Something: Stop, Note, Report, Warn

MARSAFEMARSAFESea Safety
Public Awareness
Lesson 3

If You Find Something: Stop, Note, Report, Warn

You will never need to know what an object is. You only need to know what to do in the first two minutes.

Principle

Recognition is not your job

Public safety messaging deliberately avoids teaching people to identify items. Trying to work out what something is means getting closer, looking longer and sometimes handling it — which is exactly the behaviour that causes casualties. Treat any unfamiliar metal object in or from the water as dangerous and act on that assumption. Being wrong costs you an hour of an official's time. Being right and getting closer can cost your life.

Behaviour

What actually causes accidents

Almost all civilian casualties follow deliberate contact: bringing an item ashore, hauling it aboard, moving it off a path, striking it, heating it, cutting it for scrap, or taking it home as a souvenir. Photographs from close range and crowds gathering around a find both raise the number of people exposed.

Response

The first two minutes

Distance, position, report, warn — in that order. Everything else, including whether it is genuinely a munition and what happens to it next, is decided by the authorities and the specialists they call in.

If you find something — four steps, in order
  1. Stop and stay back. Do not touch it, lift it, kick it, tie a rope to it or bring it ashore. Move away and keep others away, including children, pets and curious onlookers.
  2. Note where you are. From a safe distance, record your position — a GPS point, a photograph of the wider area, or a landmark description. Do not approach to get a better picture.
  3. Report it immediately. Call the police, coastguard or maritime authority for your country. They will pass it to the people trained to deal with it.
  4. Warn others until help arrives. Tell the harbour master, dive centre, beach operator or vessel crews nearby, and follow whatever instructions the authorities give you.
Remember this

Stay back, note the position, report it, keep others away. Four steps, always in that order, whatever the object.

MARSAFE · Public awarenessLesson 3 of 4

Practical Exercise

Write the four steps on a card in your own words, in the language your community speaks, with the correct local emergency number filled in. Share it with one person who works on the water.

Summary

The safe public response is distance, position, report, warn. Identification, handling and transport are never the public's role.

Resources for this lesson

Web link

Lesson content: 1.3 3. If You Find Something: Stop, Note, Report, Warn

Open resource
Lesson 4

1.4 4. Reporting It Well: Journalists, NGOs and Communities

MARSAFEMARSAFESea Safety
Public Awareness
Lesson 4

Reporting It Well: Journalists, NGOs and Communities

Coverage and campaigning can save lives or quietly endanger them. The difference lies in a few editorial choices.

Accuracy

Get the frame right

Distinguish clearly between what is confirmed, what is suspected and what is unknown — sources often cannot tell you more than 'an object consistent with a munition'. Attribute assessments to the authority or specialist making them, use the response steps as the practical takeaway of every story, and resist the pull towards either alarm or reassurance. Both distort behaviour.

Care

Choices that change outcomes

Publishing precise coordinates or detailed directions to a find can attract scrap collectors and sightseers to a hazard. Close-up imagery normalises approach; wide shots and official handout images do not. Avoid framing that treats a find as a curiosity or a souvenir story, and never platform someone demonstrating how they handled an item. When interviewing survivors and bereaved families, remember they are trauma sources, not colour.

Advocacy

Where NGOs add value

Risk education in schools and harbours, translated materials, reporting-route posters at slipways and dive centres, survivor support, and pressing for the surveys that let coastal projects proceed safely. Work through the national authority rather than around it, and be honest that clearance itself has environmental costs to be weighed.

Remember this

Good coverage separates fact from assumption, keeps audiences away from the hazard, and always ends with the reporting route.

MARSAFE · Public awarenessLesson 4 of 4

Practical Exercise

Draft a six-point newsroom or NGO checklist for covering an underwater munitions find, covering sourcing, location detail, imagery, the safety message, survivor interviews and the reporting number.

Summary

Responsible coverage and campaigning verify carefully, withhold hazard-guiding detail, choose imagery that does not invite approach, and always carry the reporting route.

Resources for this lesson

Web link

Lesson content: 1.4 4. Reporting It Well: Journalists, NGOs and Communities

Open resource

Quiz & assessments

Knowledge Check: Mines in the Water

Passing score 70%