Beneath the Build: Underwater Explosive Ordnance Risk for Marine Development

Lesson 1

1.1 Why Seabed Ordnance Becomes a Project Risk

MARSAFEUnderwater EO
Risk Management

Module 1 · Lesson 1.1

Why Seabed Ordnance Becomes a Project Risk

Underwater explosive ordnance only becomes a project issue when a credible seabed hazard and a planned seabed interaction overlap. That overlap is what marine developers manage.

Why it mattersLegacy ordnance can affect safety, programme, cost, permitting and investor confidence.

Where it appearsHarbours, approaches, estuaries, cable corridors, wind farm sites and inland waters.

What this course doesBuilds the judgement to recognise when specialist support is needed — nothing more.

Context

From hazard to project risk

Ordnance on the seabed may originate from conflict, naval activity, training, accidental loss or historic disposal. For a developer the question is not whether an item might exist somewhere, but whether the planned work could credibly interact with it. Dredging, piling, trenching, cable lay, anchoring, foundation works and sampling each disturb the bed differently, so the same legacy hazard produces very different project risks.

Practice

What non-specialists actually need

Project managers do not identify munitions. They recognise when a credible concern should trigger specialist review, understand that survey data has limits, and ensure controls are planned before intrusive work starts.

Consequence

The commercial dimension

Unresolved uncertainty delays mobilisation, extends vessel standby, interrupts construction, complicates insurance and attracts scrutiny. Managing the risk early protects both people and project economics.

Key takeaway

Underwater ordnance becomes a project issue where a credible hazard and a planned seabed interaction meet. Awareness is knowing how to spot that point early.

Practical Exercise

Choose one project type — port expansion, offshore wind, subsea cable, dredging or reclamation. List three activities that interact with the seabed and, for each, the management question the team should ask about possible explosive ordnance. Do not attempt to identify or investigate any object.

Summary

Ordnance risk arises where a credible hazard overlaps with planned seabed interaction. Early awareness supports safer planning, better specialist engagement and fewer late surprises.

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Lesson content: 1.1 Why Seabed Ordnance Becomes a Project Risk

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Lesson 2

1.2 Reading the Evidence: History, Charts and Uncertainty

MARSAFEUnderwater EO
Risk Management

Module 1 · Lesson 1.2

Reading the Evidence: History, Charts and Uncertainty

Marine ordnance risk usually begins in the archive. Evidence is essential, incomplete, and only useful once it is tied to a specific footprint and work method.

EvidenceMilitary records, charts, wreck data, previous works and modern survey.

UncertaintyRecords may be lost, imprecise, or written for a different purpose.

ChangeBurial, scour, erosion and sediment movement alter present-day conditions.

Sources

Where historical risk originates

Ports, naval bases, shipping approaches, coastal batteries, bombing targets, former minefields, training areas and engagement zones are all relevant. Deliberate post-conflict dumping adds a different kind of legacy. The task is to reconstruct a defensible site history rather than rely on a single map, database entry or anecdote.

Method

Why evidence must be triangulated

No single source is complete. Records may describe intended minefields rather than final positions, report attacks across broad areas, or omit later clearance and redevelopment. A strong desk assessment compares sources and records contradictory evidence as carefully as supporting evidence.

Output

From archive to conceptual site model

Research becomes useful when linked to geography, seabed conditions and the planned works, producing a view of where hazards may plausibly sit, where uncertainty remains, and which questions field work must answer.

Key takeaway

Historical research reduces uncertainty when multiple sources are compared and connected to the project footprint, working depth and seabed conditions.

Practical Exercise

Build a simple evidence map for a former naval harbour: three categories of historical or modern information, what each could tell you, and one uncertainty that would remain.

Summary

Evidence is essential but rarely perfect. Strong assessment compares sources, records uncertainty and ties historic activity to the real project footprint.

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Lesson content: 1.2 Reading the Evidence: History, Charts and Uncertainty

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Lesson 3

1.3 Roles, Competence and Professional Boundaries

MARSAFEUnderwater EO
Risk Management

Module 1 · Lesson 1.3

Roles, Competence and Professional Boundaries

Safe delivery depends on knowing who decides, who advises, who may stop work — and where awareness ends and operational competence begins.

AwarenessRecognise the risk and understand the management process.

Project dutyPlan, document, communicate and procure competent support.

Specialist dutyOperational tasks require formal competence and authorisation.

Accountability

Who is responsible for what

Developers, designers, contractors, vessel operators, survey teams, regulators and specialist organisations hold different responsibilities. A robust project states these explicitly instead of assuming the specialist contractor absorbs every risk.

Competence

Competence is task-specific

Marine surveying, diving, ordnance risk assessment and disposal are separate disciplines. Projects should define which competence each task requires and confirm the organisation is authorised to perform it.

Governance

What good governance looks like

Approved procedures, defined communication routes, stop-work authority, quality management, documented handover, and clear escalation to competent specialists and relevant authorities.

Key takeaway

Safe delivery rests on defined responsibilities and task-appropriate competence, not on having a specialist somewhere in the supply chain.

Practical Exercise

Draft a responsibility map for a developer, vessel operator, survey contractor and ordnance specialist. Give each one awareness-level responsibility and identify who owns the final risk decision.

Summary

Awareness supports recognition and escalation. Operational work requires task-specific competence, authorisation, approved procedures and clearly assigned responsibility.

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Lesson content: 1.3 Roles, Competence and Professional Boundaries

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Lesson 4

2.1 The Risk Management Lifecycle: Desk Study to Survey

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Risk Management

Module 2 · Lesson 2.1

The Risk Management Lifecycle: Desk Study to Survey

Risk management is a staged decision process. Each stage should reduce uncertainty just enough to support the next project decision — no more, no less.

ScreenEstablish whether a credible concern exists at all.

AssessConnect the evidence to the planned seabed interaction.

VerifyUse survey and interpretation to close the gaps that matter.

Framework

A lifecycle, not a single survey

Professional practice may run from early screening and historical assessment through data review, risk assessment, survey design, anomaly assessment, specialist investigation where justified, mitigation, assurance and reporting. Not every project needs every stage; effort should match the credible hazard, the uncertainty, the work method and the consequences.

Evidence

What a desk study must deliver

Useful sources include military archives, historic charts, bombing and mine records, wreck data, previous project reports, hydrographic and geological data and modern survey datasets. Sources differ in precision, date and purpose, and a professional assessment says so. The study should end with project implications and evidence gaps, not a history chapter.

Limits

What survey can and cannot promise

Geophysical and visual methods characterise seabed conditions and identify anomalies worth assessing. Performance is affected by burial, sediment, debris, sensor configuration, coverage and conditions, so specifications should state objectives, quality expectations and known limitations in advance. Raw detections become decisions only through specialist interpretation.

Key takeaway

The lifecycle exists to reduce uncertainty progressively and to make each project decision defensible on the evidence available at the time.

Practical Exercise

For a harbour with wartime military history now planned for dredging, write five desk-study questions that would show whether further specialist assessment is justified, plus three factors that could reduce confidence in survey interpretation there.

Summary

Risk management is a staged process running from screening to documented assurance. Desk study builds the evidence base; survey reduces uncertainty within stated limits.

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Lesson content: 2.1 The Risk Management Lifecycle: Desk Study to Survey

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Lesson 5

2.2 Standards and Proportionate Control

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Risk Management

Module 2 · Lesson 2.2

Standards and Proportionate Control

IMAS 09.60 gives clients and contractors a common professional benchmark. Controls chosen against it should be proportionate — the most complex option is rarely the best one.

BenchmarkIMAS 09.60 covers underwater survey and clearance of explosive ordnance.

Not a substituteNational law, permits and client requirements still apply in full.

ProportionAvoid first, reduce uncertainty next, intervene only where justified.

Standards

Why a recognised standard helps the client

Standards set a shared expectation for planning, competence, safety, quality and documentation — valuable when partners come from different institutional backgrounds. They sit alongside national legislation, maritime and diving regulation, environmental permissions and occupational safety law, not above them. In procurement they let a client ask for evidence of capability rather than a statement of compliance.

Design

Avoidance is a design decision

Early flexibility can remove the interaction altogether. Route optimisation, footprint changes and exclusion areas are often the cheapest and safest controls when they remain technically and commercially feasible.

Escalation

Mitigation and clearance

Where avoidance is insufficient, projects use further assessment, revised methods, additional controls, monitoring or specialist support matched to the specific risk pathway. Where credible ordnance cannot be avoided and materially affects the works, authorised specialist intervention may be required — a decision that sits inside legal, environmental, safety and governance arrangements.

Key takeaway

IMAS 09.60 is a benchmark, not a permit. Applied with national law and competent judgement, it makes proportionate control decisions defensible.

Practical Exercise

For a marine route with several unresolved anomalies, propose two design-level avoidance options and two management-level mitigation options, and state what evidence you would need before choosing between them.

Summary

IMAS 09.60 provides a professional benchmark to be applied alongside national law. Control should begin with avoidance and escalate only as evidence and project need justify.

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Lesson content: 2.2 Standards and Proportionate Control

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Lesson 6

2.3 Preparedness, Stakeholders and Residual Risk

MARSAFEUnderwater EO
Risk Management

Module 2 · Lesson 2.3

Preparedness, Stakeholders and Residual Risk

Unexpected findings are manageable when the response, the audiences and the remaining uncertainty were all defined before mobilisation.

BriefEvery relevant person knows the reporting route before work starts.

IntegrateEnvironmental, regulatory and stakeholder duties run alongside safety.

DeclareResidual risk is described and handed over, never assumed to be zero.

Response

Plan the response before mobilisation

Establish who can stop work, who receives the first report, who calls specialist support and who authorises restart. Non-specialists need a simple instruction set: avoid disturbance, report through the approved chain, follow project controls. Complex judgements belong with authorised specialists.

Integration

Environment, regulation, stakeholders

Controls interact with marine ecology, noise, protected areas, heritage, fisheries and navigation, and with marine licensing, explosives control, diving rules and coastguard or military notification. Communication should separate confirmed fact from uncertainty, avoiding both alarm and false reassurance.

Continuity

Documentation, handover and residual risk

Desk assessments, risk registers, survey specifications, anomaly registers, mitigation decisions, permits and briefings exist so another competent person can reconstruct what was decided and why. Handover must carry limitations, outstanding actions and mandatory controls into the next phase in language the receiving team can use. Controls reduce risk; they rarely remove it entirely, and the remainder must be stated.

Key takeaway

A project is not risk-managed until its assumptions, controls and residual risk are documented and handed to the people who will work on top of them.

Practical Exercise

Prepare a six-point awareness briefing for a marine crew, then identify four stakeholder groups for a port redevelopment and one concern each may raise about ordnance risk management. Keep everything non-operational.

Summary

Preparedness, integrated regulatory and stakeholder handling, and honest documentation of residual risk are what carry safety across project phases.

Resources for this lesson

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Lesson content: 2.3 Preparedness, Stakeholders and Residual Risk

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