Regulatory Playbook
MARITIME OT CYBERSECURITY IEC 62443-3-2 RISK ASSESSMENT PLAYBOOK
Why Maritime OT Cybersecurity Needs Its Own Playbook
A vessel's engine room and a port terminal's crane yard were never built with connectivity in mind. Propulsion automation, ballast control, cargo handling systems, and terminal cranes were designed for decades of isolated, deterministic operation , closed loops that didn't need to talk to anything outside themselves. Engineers who built these systems assumed physical isolation would always be the primary control: if a system wasn't wired to anything else, it couldn't be reached by anything else. That assumption held for a long time. It doesn't hold anymore.
Satellite connectivity, OEM remote diagnostics, shore-side terminal integrations, and shared network infrastructure now touch nearly every one of those systems, whether anyone planned for it or not. A main engine OEM wants a standing connection for predictive maintenance. A terminal operating system needs to talk to crane PLCs in real time to keep berth productivity on target. Crew welfare Wi-Fi shares a switch with systems that were never meant to be reachable from a personal device. None of these connections were added maliciously , each solved a real operational or commercial problem. But collectively, they've quietly dissolved the isolation that used to be the primary line of defense.
This convergence happened faster than the sector's risk management maturity could keep pace with. Most ports, terminals, and fleet operators today have a firewall diagram and perhaps a policy document, but no register that actually ties assets to threats, vulnerabilities, and a scored, owned, tracked risk. When an incident does occur, or when an auditor asks a direct question, that gap becomes very visible very quickly.
Why IEC 62443-3-2 Fits Maritime OT So Well
A vessel's engine room and a port terminal's crane yard were never built with connectivity in mind. Propulsion automation, ballast control, cargo handling systems, and terminal cranes were designed for decades of isolated, deterministic operation. That isolation is gone. Satellite connectivity, OEM remote diagnostics, shore-side terminal integrations, and shared network infrastructure now touch nearly every one of those systems, whether anyone planned for it or not.
Regulators have noticed the gap. IMO Resolution MSC.428(98) requires cyber risk to be addressed within existing Safety Management Systems. IACS Unified Requirements E26 and E27 are pushing new-build vessels toward IEC 62443-aligned cybersecurity design. Flag states, port state control inspectors, and class societies increasingly expect a documented, repeatable risk assessment, not a firewall diagram and a policy binder.
Most ports, terminals, and fleet operators still lack the one thing that ties everything together: a register that connects real assets to real threats, real vulnerabilities, and a scored, owned, tracked risk. That gap shows up as failed audits, unanswered underwriter questions, and, in the worst case, an incident where nobody had mapped the blast radius of a compromised OEM connection until it was too late.
Why You Should Download This Playbook
This is a working playbook, not a summary of the standard. It's built specifically around how vessels and terminals are actually structured , bridge and navigation, propulsion and machinery control, cargo and ballast systems, terminal OT, and the communications gateways that stitch them all together.
IEC 62443-3-2 was written for industrial control systems in general, not ships and ports specifically. But its zone-and-conduit methodology maps onto maritime architecture almost perfectly, because the physical and functional separation already exists. What's usually missing isn't the boundary, it's the documentation, the risk scoring, and the discipline to keep it current as systems change.
Inside, the complete assessment cycle is laid out chapter by chapter, covering:
Scope Definition, defining the assessment boundary, stakeholder involvement, and safety-critical system handling before any inventory work begins.
Asset Inventory, capturing every asset that can send, receive, process, or store data, including the OEM gateways and USB interfaces most inventories miss.
Threat Register, translating generic maritime threat categories into scenarios specific to real assets and entry vectors.
Vulnerability Register , validating every weakness against a real asset rather than importing a generic industrial list.
Zone & Conduit Segmentation , partitioning bridge, engine, cargo, terminal OT, and IT systems into zones with documented conduit controls.
Executive Summary Report & Final Checklist, reporting results to leadership and verifying the assessment is audit-ready.
Key Takeaways from the Playbook
Scope is a deliverable, not an assumption. Every assessment that goes sideways starts with scope that was assumed rather than formally agreed between the asset owner, the assessment lead, and the people who run the vessel or terminal day to day.
Your asset inventory is probably missing the riskiest things on it. OEM remote diagnostics gateways, USB transfer points, VSAT terminals, and legacy serial-to-Ethernet converters are the categories left off inventories most often , precisely because nobody on staff considers them theirs to track.
Threats need to be specific to be useful. "Ransomware" as a line item tells you nothing. "Ransomware delivered via a compromised OEM remote diagnostics connection to the main engine automation system" tells you exactly what to test, segment, and monitor.
Zones and conduits are the structural backbone of the whole exercise. Get the zone model right before scoring risk, or the risk register turns into an unstructured list nobody can act on.
Safety-critical systems get handled differently. Emergency shutdown, fire and gas detection, and steering redundancy systems should be inventoried and risk-scored but excluded from active scanning or intrusive testing, in line with standard shipboard safety practice.
Treatment has to respect drydock reality. Many maritime OT fixes can only happen during a scheduled drydock or maintenance window, a generic 30/60/90-day target that operations doesn't believe is achievable will not get executed.
A risk assessment is a living document. A retrofit, a new OEM integration, a drydock upgrade, or a change in fleet management provider should trigger a targeted reassessment of the affected zones, not wait for next year's annual cycle.
Who Should Download This Playbook
This playbook is built for the people who actually own maritime cyber risk, in whatever form that ownership takes:
Port and terminal OT engineers responsible for asset inventory, zone mapping, and treatment execution across cranes, gate systems, and terminal operating systems.
Vessel operators and fleet superintendents applying a consistent methodology across vessel classes and bridge, propulsion, and cargo systems.
CISOs and security directors who own the risk register, approve treatment plans, and report residual risk to leadership and boards.
Compliance and SMS managers building evidence for IMO MSC-FAL.1/Circ.3, IACS UR E26/E27, flag-state audits, and port-state control inspections.
System integrators and consultants who need a structured, repeatable framework to standardize delivery across multiple port or vessel engagements.
How Shieldworkz Supports Your Maritime OT Security Program
Reading a playbook is one thing. Executing it across a live vessel, a working terminal, or a multi-ship fleet , without disrupting operations , is another. Shieldworkz's OT security architects have run exactly this kind of engagement across ports, terminals, and vessel operators, and we bring field-tested judgment to every stage: knowing when active scanning is safe and when it isn't, knowing which OEM relationships tend to introduce the most standing risk, and knowing how to write a treatment plan that survives contact with a drydock schedule.
Through our OThello Assess methodology, we help maritime organizations run the full IEC 62443-3-2 cycle , scoping, asset inventory, threat and vulnerability analysis, zone and conduit segmentation, risk scoring, and treatment planning , backed by real-world OT and IoT threat intelligence and a global research team that tracks the threat actors actually targeting shipping and port infrastructure.
Download the Guide and Book Your Free Consultation
Fill out the form to get the complete Maritime OT Cybersecurity IEC 62443-3-2 Risk Assessment Playbook. Inside, you'll find practical, ready-to-use worksheets for asset inventory, threat and vulnerability registers, a 5×5 risk matrix, a risk treatment plan template, and a residual risk log to help you perform a structured, standards-aligned OT cybersecurity risk assessment for ports, terminals, and vessels.
Then take the next step and talk to someone who's done this on real vessels and real terminals.
Schedule a Demo With Shieldworkz OT Security Experts
Find out where your current maritime OT risk assessment has gaps , before an auditor, an insurer, or an attacker finds them for you.
Download your copy today!
Download the Maritime OT Cybersecurity IEC 62443-3-2 Risk Assessment Playbook to assess cyber risks, strengthen resilience, and support IEC 62443-aligned maritime operations.
