Maritime Collision Claims Greece 2026: Liability, COLREGS Breaches and Evidence Preservation

Maritime collision claims Greece practitioners face in 2026 remain concentrated in one principal casualty forum, Piraeus, where the interplay of the international collision regulations, Greek substantive law and increasingly technical electronic evidence determines who pays and how much. There is no new statute reshaping the landscape this year, but the practical demands on shipowners, Protection and Indemnity (P&I) clubs, Hull and Machinery (H&M) underwriters, masters and in-house claims teams have sharpened around one issue above all: preserving Voyage Data Recorder (VDR), Electronic Chart Display and Information System (ECDIS) and Automatic Identification System (AIS) evidence before it is overwritten, degraded or lost.

This guide sets out how liability is apportioned under the International Regulations for Preventing Collisions at Sea (COLREGs) in Greece, what evidence Greek courts and arbitrators rely on, and the procedural steps for arrest, security and running a claim. The aim is a jurisdiction-specific playbook you can act on within the first 24 hours of a casualty.

1. Quick legal framework: collision law in Greece and the applicable rules

Any assessment of maritime collision claims Greece courts will entertain begins with two overlapping bodies of rule: the international navigational standard set by COLREGs, and the Greek national law that governs procedure, prescription and, often, the substantive allocation of loss. Understanding which layer applies to a given issue is the first analytical step in any casualty file.

Applicable international rules (COLREGs)

The International Regulations for Preventing Collisions at Sea, adopted through the International Maritime Organization (IMO), provide the universal standard of good seamanship against which vessel conduct is judged. They apply to all vessels on the high seas and connected navigable waters, and Greek tribunals treat the rules, the look-out obligation, safe speed, risk-of-collision assessment, action to avoid collision, and the steering and sailing rules for overtaking, crossing and head-on situations, as the substantive yardstick of fault. A breach of a COLREGs rule does not by itself establish liability; it must be shown to have caused or contributed to the collision.

Interaction with Greek national law and courts

Where a collision has a Greek nexus, vessels in Greek territorial waters, a Greek-flagged ship, a defendant with assets in Greece, or an arrest in a Greek port, Greek procedural law governs how the claim is brought, how evidence is disclosed and how security is obtained. Greek statutes and implementing measures are published in the Government Gazette, and the substantive apportionment principles applied by Greek judges draw on both the collision regulations and domestic maritime and civil law. In many cases the applicable substantive law depends on where the collision occurred and the flags involved; counsel should resolve the governing-law question early, because it affects both the standard of fault and the limitation period.

Greece is also a party to a number of international maritime conventions relevant to collision and liability, and whether a particular convention applies to a given casualty should be confirmed on the facts rather than assumed.

Limitation periods (statute of limitations)

Time bars in collision matters vary by the nature of the claim, property damage, personal injury and cargo claims may each attract different prescription periods under Greek law and any applicable international convention. Because limitation can extinguish an otherwise strong claim, and because the calculation depends on the governing law and claim type, the safe course is to treat every casualty as time-critical: preserve rights, obtain security and instruct Greek counsel to confirm the precise limitation position rather than relying on a rule of thumb.

2. COLREGS breaches and proving fault: Greek practice and apportionment

The heart of most maritime collision claims Greece tribunals decide is a factual and technical contest over which vessel breached the collision regulations and to what degree that breach caused the casualty. Greek courts and arbitrators apply COLREGs as the substantive standard of care, then apportion liability in proportion to fault where both vessels are found to have contributed.

Most-cited COLREGS rules in collisions

Part B of the collision regulations, the steering and sailing rules, generates the overwhelming majority of arguments. The rules most frequently invoked in Greek collision proceedings include:

• Look-out. The requirement to maintain a proper look-out by sight, hearing and all available means, including radar and AIS. A failure of look-out is the most common single allegation and often the most damaging.
• Safe speed. The obligation to proceed at a speed that permits proper and effective action to avoid collision and stopping within a distance appropriate to prevailing conditions.
• Risk of collision. The duty to use all available means to determine whether risk of collision exists, including proper use of radar and systematic observation.
• Action to avoid collision. Requiring positive, timely and readily apparent action, made in ample time and with due regard to good seamanship.
• Overtaking, head-on and crossing rules. Which vessel is the give-way vessel and which is the stand-on vessel, and the obligations of each in the developing encounter.

Because these rules interlock, a defence rarely turns on a single rule; the tribunal weighs the conduct of both vessels against the full sequence of the encounter.

Burden and standard of proof in Greece

The claimant bears the burden of proving both breach and causation. In practice, this means reconstructing the encounter minute by minute from the electronic record and establishing that the breach alleged made a material difference to the outcome. Greek tribunals will scrutinise the seamanship of each vessel, the adequacy of the look-out, and the timing and quality of avoiding action. Contemporaneous electronic data, the VDR, ECDIS and AIS records, carries decisive weight precisely because it is far harder to challenge than recollection.

Apportionment methodology and examples

Where both vessels are at fault, Greek courts apportion liability in proportion to the degree to which each vessel’s fault contributed to the collision. The exercise is comparative: the tribunal assesses the relative causative potency of each breach rather than mechanically counting rule violations. A vessel that failed to keep a proper look-out and also proceeded at excessive speed in restricted visibility will typically carry a heavier share than a vessel that made a single, less causative error. Where one vessel’s conduct is overwhelmingly responsible, apportionment may approach or reach full liability.

Reported Greek collision judgments, including decisions of the Areios Pagos (the Supreme Civil and Criminal Court), illustrate that apportionment is intensely fact-specific and depends on the causative weight the court attaches to each established breach.

Role of expert evidence (master mariner, naval architect)

Expert evidence is central. A master mariner reconstructs the navigational encounter, interprets the VDR and radar record, and opines on whether the conduct of each vessel met the standard of good seamanship. A naval architect may address stability, structural damage and the physics of the impact. In Piraeus practice, the quality of the reconstruction expert frequently determines the outcome, because the tribunal relies on the expert to translate raw electronic data into a coherent, causation-focused narrative. Instructing a credible, independent expert early, before the data is lost, is one of the highest-value decisions a claims team can make.

3. Evidence preservation: VDR, ECDIS, AIS, logbooks and watchkeeping records

Evidence preservation is where maritime collision claims Greece cases are most often won or lost. Electronic navigational data is fragile: VDR memory overwrites on a cycle, AIS shore logs are held by third parties on their own retention schedules, and ECDIS records can be altered by continued operation. The first hours and days are decisive. The following protocol sets out who does what and when.

Immediate steps (first 24 hours)

Within the first 24 hours after a collision, the master and owner should, as an ordered sequence:

1. Notify the P&I club and owner’s designated casualty response line immediately, and notify the Hellenic Coast Guard as the competent Greek authority for casualty reporting and investigation.
2. Instruct the master in writing to preserve the VDR recording and prevent overwriting, this is the single most urgent technical step.
3. Secure the VDR power supply so the unit is not depowered in a way that risks data loss, and follow the manufacturer’s preservation procedure.
4. Freeze and secure all logbooks, the passage plan, chart records, movement books and rough notes, and take custody of them in a controlled location.
5. Collect watchkeeper and bridge-team accounts while memories are fresh, but under legal privilege where possible.
6. Photograph and video the damage on both vessels where accessible, with timestamps.

VDR: what to preserve, who downloads, format and chain of custody

The Voyage Data Recorder is the black box of the maritime casualty. IMO VDR guidance describes the data the unit captures, bridge audio, radar image, ECDIS data, heading, speed, position, rudder and engine orders and more, and underlines that the recorded period is finite and cyclical, so the data must be secured before it is overwritten. The master should activate the save or preservation function immediately after the incident. Do not rely on the vessel’s crew to perform the forensic extraction: engage a qualified forensic technician, ideally one instructed jointly or with the P&I club’s approval, to make a certified forensic copy of the raw data.

Record every step, who handled the unit, when the save function was activated, when and by whom the download was made, and where the media was stored. A documented, unbroken chain of custody is what makes the VDR data admissible and persuasive before a Greek court or arbitral tribunal; a gap in that chain invites a challenge to authenticity.

ECDIS screenshots and route data (how to secure)

The Electronic Chart Display and Information System holds the planned and actual track, waypoints, alarms and route data. Because ECDIS continues to operate and log after the casualty, secure its record promptly: export the voyage recording and route file in native format, capture screenshots of the relevant displays, and note the software version and chart edition in use at the time of the collision. Native export is preferable to screenshots alone, because it preserves the underlying data for expert analysis, but capture both.

AIS: raw data, shore-side logs and third-party providers

Automatic Identification System data exists in two forms: the record on board and the record held by shore stations and third-party tracking providers. The shore-side logs are held by others on their own retention cycles, so a preservation request to the relevant authority or commercial provider should go out within the first days. AIS provides an independent, timestamped position-and-track record that corroborates or contradicts the VDR and witness accounts, and its independence from either vessel makes it especially valuable in contested causation.

Logbooks, passage plans, watchkeeping statements and medical reports

Physical and documentary records remain essential alongside the electronic data. Preserve the deck and engine logbooks, the passage plan, the movement book, standing and bridge orders, watch schedules, and any medical reports where injury is involved. Take detailed statements from the bridge team as soon as practicable, recording what each watchkeeper saw, heard and did, and preserve any rough working notes rather than only the fair copies, since discrepancies between the two are frequently probative.

Forensic experts and preserving evidence for arbitration

Where the dispute is destined for arbitration under a charterparty or contractual clause, the same preservation discipline applies, and early instruction of forensic and nautical experts is if anything more important, because arbitral tribunals rely heavily on the parties’ technical evidence. Preserve raw data in native format, avoid working on original media, and maintain the chain-of-custody record from the outset. When must VDR downloads be preserved to be admissible? The practical answer is immediately, activate preservation within hours and complete the certified forensic download as soon as possible, well before the recording cycle risks overwriting the casualty period.

4. Greece-specific process: arrest, security, letters of undertaking and jurisdiction

Once liability and evidence are in hand, the commercial contest turns on securing the claim. In maritime collision claims Greece practitioners run, Piraeus is the natural forum for ship arrest and the negotiation of security, and the mechanics are well established.

Arrest procedure (brief steps)

Ship arrest is a routine and effective remedy in Greek ports. In outline, a claimant applies to the competent Greek court for an order authorising conservative arrest of the vessel to secure the claim, demonstrating the maritime claim and the need for security. The arrest immobilises the vessel until security is provided or the court orders release. The relevant procedural provisions are found in Greek law, including the provisions of the Code of Civil Procedure on conservatory (provisional) measures, and speed matters: a vessel calling at Piraeus may sail within hours, so an arrest application must be prepared and filed without delay.

Coordinating the arrest with the evidence-preservation steps above ensures that the vessel is not released before critical data has been secured.

Letters of Undertaking versus cash security

In practice, most collision claims are secured not by cash or bank guarantee but by a Letter of Undertaking (LOU) issued by the defendant owner’s P&I club. An LOU is a written promise by the club to pay any sum found due, up to an agreed figure, in exchange for the claimant refraining from or releasing an arrest. LOUs from reputable clubs are commonly accepted in Greek practice because they avoid the cost and delay of cash security while giving the claimant a solvent, enforceable commitment. The negotiation typically covers the amount, the wording of the undertaking, the governing law and jurisdiction of the LOU, and the trigger for payment.

When an arbitration clause applies; jurisdiction and forum

Where the parties are bound by a contractual arbitration clause, common in charterparty-related disputes, the substantive dispute may proceed to arbitration even while security is obtained through the Greek courts. Greece offers established maritime arbitration, and the Hellenic Chamber of Shipping arbitration provides a recognised local framework. The choice between litigation in the Greek courts and arbitration turns on the contractual documents, the desirability of confidentiality and specialist tribunals, and enforcement considerations. For the procedural mechanics of commencing arbitration in Greece, see our maritime arbitration in Greece, full procedural guide.

Piraeus court timings and practicalities

Piraeus is the operational centre of Greek shipping litigation, with courts and practitioners experienced in casualty work. Provisional and conservatory measures such as arrest can be obtained quickly, while substantive proceedings follow the ordinary rhythm of Greek civil procedure. The practical takeaway is to separate the urgent security phase, handled fast, in Piraeus, from the slower substantive determination of liability and quantum.

5. Collision versus allision: legal difference, liability and examples in maritime collision claims Greece

A recurring source of confusion in maritime collision claims Greece files is the distinction between a collision and an allision. The difference is not merely terminological; it changes the causation analysis, the evidence you gather and the parties you sue.

When is it an allision?

A collision, strictly, is contact between two moving vessels. An allision is contact between a moving vessel and a fixed or stationary object, a berth, a jetty, a bridge, an aid to navigation or an anchored vessel. Because the struck object is stationary and cannot manoeuvre, the causation analysis usually focuses on the conduct of the moving vessel, and liability more often falls unilaterally on that vessel. That said, allision cases can still involve third-party fault, a defective berth, an improperly lit or marked structure, or negligent port operations, so the analysis is not automatically one-sided.

Implications for apportionment and damages

In a collision, mutual apportionment under COLREGs is common, and cross-claims between the two vessels are the norm. In an allision, apportionment is often unnecessary because liability rests with the striking vessel, but the claim frequently brings in port authorities, terminal operators or property owners as claimants or additional defendants, and the evidence set expands to include berth logs and waterfront records. The comparison below summarises the practical differences.

6. Running the claim in Greece: timeline, disclosure, experts, costs and recoveries

Once security is in place and evidence preserved, the substantive claim proceeds. Running maritime collision claims Greece tribunals will resolve requires a clear view of the litigation-versus-arbitration choice, the disclosure regime, the role of experts and the interplay of insurance.

Litigation versus arbitration in the Greek context

Both routes have a place. Litigation in the Greek courts is the natural home for tortious collision claims without an arbitration agreement, and Piraeus judges are experienced in casualty work. Arbitration is contractual and suits charterparty-linked disputes where confidentiality, specialist tribunals and cross-border enforcement matter. The advantages and disadvantages track the usual axes, cost, speed, confidentiality, appeal rights and enforceability, and the choice is frequently dictated by the underlying contracts rather than being a free election.

Evidence exchange and disclosure norms

Greek civil procedure does not replicate common-law-style broad discovery; documentary evidence is produced and relied upon by the parties, and the tribunal weighs what is put before it. This makes the party-led preservation and production of VDR, ECDIS and AIS data all the more important, because there is no automatic mechanism that will compel a reluctant opponent to disclose a full electronic record. A well-timed pre-action preservation letter, coupled with security, protects the claimant’s evidential position.

Typical timeline and interim relief

The typical arc runs from the casualty, through immediate evidence preservation and arrest or LOU negotiation, to the exchange of expert reports and pleadings, and finally to judgment or arbitral award. Interim relief, principally conservative arrest, is obtained early and quickly, whereas the substantive determination proceeds over a longer horizon. Building the case around the electronic reconstruction from the outset shortens the substantive phase, because the factual matrix is fixed early.

Costs, recoveries and limitation

Recoveries in collision matters flow through the marine insurance structure. H&M underwriters indemnify the owner’s own hull damage and may pursue recovery from the other vessel by subrogation, while the P&I club responds to third-party liabilities including the collision liability the owner owes to the other vessel and to injured parties. Coordinating H&M and P&I positions, who leads the recovery, how costs are shared, and how any LOU is called, is a core part of running the claim efficiently. Throughout, keep the limitation position under review, because a lapse of the prescription period can defeat even a fully evidenced recovery.

7. Practical checklist and an immediate 24-hour action plan

For masters, owners, P&I and in-house counsel, the following ten-point checklist distils the priorities of the first hours of a maritime collision claims Greece response:

1. Notify the P&I club and owner’s casualty response line immediately.
2. Report to the Hellenic Coast Guard and comply with casualty-reporting obligations.
3. Instruct the master in writing to preserve the VDR and prevent overwriting.
4. Secure the VDR power supply and arrange a certified forensic download as soon as possible.
5. Export and secure ECDIS route data and screenshots in native format, noting software and chart editions.
6. Send AIS preservation requests to shore authorities and third-party providers.
7. Freeze and take custody of logbooks, passage plan, movement book and rough notes.
8. Take contemporaneous bridge-team statements under legal privilege where possible.
9. Instruct a nautical expert to begin the reconstruction and assess COLREGs breaches and causation.
10. Assess the need for arrest or security in Piraeus and prepare an LOU or arrest application without delay.

Maintain a written chain-of-custody log for every item of electronic evidence from the moment of preservation, and keep a single point of contact coordinating the technical, legal and insurance workstreams.

8. Conclusion and recommended next steps

Maritime collision claims Greece practitioners will handle in 2026 are decided less by legal argument in the abstract than by the quality and integrity of the evidence secured in the first hours and by the speed of the security response in Piraeus. The COLREGs supply the standard of fault, Greek law governs procedure, prescription and often apportionment, and the VDR, ECDIS and AIS records translate the encounter into the objective reconstruction on which liability turns. The single most valuable action a claims team can take is to preserve that data with a documented chain of custody before it is lost, and to move quickly on arrest or a Letter of Undertaking to secure the claim.

For urgent casualty assistance, instruct a Greek casualty specialist through our Shipping & Yachting Litigation practice area, and consult the author profile via the author profile for direct expertise in Piraeus collision litigation and arbitration.

Sources

1. International Maritime Organization, COLREGs (consolidated information)
2. IMO, Voyage Data Recorder (VDR) guidance
3. Hellenic Coast Guard (Λιμενικό Σώμα)
4. Hellenic Chamber of Shipping, Arbitration
5. Government Gazette, National Printing Office
6. Areios Pagos, Supreme Civil and Criminal Court of Greece