MARPOL Annex I Reg 37: SOPEP

Background: MARPOL 73/78 to consolidated 2025 edition

The Shipboard Oil Pollution Emergency Plan was not part of the original MARPOL 73/78 Convention. The 1973 instrument and the 1978 Protocol concentrated on construction, equipment, and discharge-control rules: double-bottom tanks, the oily water separator, the 15 ppm discharge ceiling, and the Oil Record Book audit trail. Spill response was treated as a coastal-State problem; the crew of a stricken ship was expected to send a distress message under SOLAS Regulation V/2 and wait for shore assets to arrive.

The Exxon Valdez grounding on 24 March 1989 changed that posture. The US Coast Guard and the National Transportation Safety Board concluded that the master had no documented response procedure on board and that the first hour of the spill was lost to confused communications. The US Oil Pollution Act of 1990 (OPA 90) responded with a national requirement for a Vessel Response Plan, and the IMO responded with the 1991 amendments to MARPOL Annex I that inserted what was then Regulation 26 (now Regulation 37) requiring every covered ship to carry a SOPEP.

The 1991 amendments entered into force on 4 April 1993, and within a year the MEPC adopted Resolution MEPC.54(32) to provide standardised content guidance. At the same 44th session of the MEPC in 2000, two further resolutions completed the framework: MEPC.86(44) amended the original SOPEP guidelines in MEPC.54(32), and MEPC.85(44) established the combined SMPEP/SOPEP for ships carrying oil and noxious liquid substances together. The plan was already integrated with the ISM Code framework when the 1998 ISM amendments to SOLAS took effect. The 2004 consolidated revision of Annex I renumbered Regulation 26 to Regulation 37 without substantive change.

The 2025 consolidated edition of Annex I carries Regulation 37 in substantively the same form it has held since 1991, with one consequential addition: alternative-fuel spill reporting now appears as an explicit cross-reference, anticipating the IGF Code amendments adopted in 2024 for methanol-fuelled and ammonia-fuelled ships.

Regulation 37 scope: 400 GT and 150 GT thresholds

The thresholds are the gateway to the regime. Regulation 37 has two limbs.

The first limb requires every ship of 400 gross tonnage and above, oil tanker and non-tanker alike, to carry a SOPEP approved by the Administration. The 400 GT threshold matches the threshold for the Oil Record Book Part I and for the IOPP Certificate. Below 400 GT a ship is not within Annex I’s structural regime, though many flag States impose national-law equivalents on smaller vessels.

The second limb requires every oil tanker of 150 gross tonnage and above to carry a SOPEP irrespective of the 400 GT threshold for non-tankers. The 150 GT threshold is the same threshold that triggers the Oil Record Book Part II and the cargo-tank regime under Regulation 28 damage stability and 33 crude oil washing. It captures small oil tankers, including coastal product carriers and bunker barges.

The Administration is the flag State of the ship. Approval is normally delegated to a Recognised Organisation, in practice the classification society holding the flag-State authorisation. The approved SOPEP carries the stamp and signature of the Administration or its delegate on the title page, and the approval is referenced in the IOPP Certificate’s Form A or Form B. A SOPEP amended substantively must be re-submitted for approval; minor contacts-list updates do not require re-approval but must be entered with the date of revision.

MEPC.54(32) and MEPC.86(44): the guidelines framework

The Guidelines adopted as Resolution MEPC.54(32) on 6 March 1992 give content to the bare regulatory requirement. MEPC.86(44), adopted at the 44th session of the MEPC in March 2000, amends those guidelines. Together they form the current content standard against which every flag-State Administration grants approval and against which every classification-society checklist is structured.

The original guidelines in MEPC.54(32) are not mandatory in the strict sense, but every flag-State Administration applies them as the standard against which approval is granted, and every Port State Control regime treats non-conformity with them as a deficiency. MEPC.86(44) brought the terminology into alignment with the ISM Code, tightened the language-of-the-plan requirement, and clarified the revision-log format that PSC inspectors use as a proxy for plan maintenance.

The combined text runs to fifteen pages and is organised into five chapters. Chapter 1 sets out the general principles, including the requirement that the plan be in the working language of the master and senior officers and that it be readily accessible from the bridge. Chapter 2 sets out the reporting requirements that must appear in Section 2. Chapter 3 covers the steps to control discharge that appear in Section 3. Chapter 4 covers the contacts and authorities that appear in Section 4. Chapter 5 covers the introductory material in Section 1.

The guidelines specify that the plan must address spills resulting from operational discharges that exceed permissible limits and spills resulting from casualties. They also specify that the plan must contain ship-specific information, not generic text: the ship’s name, IMO number, gross tonnage, type, fuel-tank arrangement, and the location of pollution-response equipment.

SOPEP required contents: a reference table

Regulation 37.1 mandates four elements in the plan. The table below maps each regulatory element to the section of the plan and to the instrument that specifies its content.

Every element in the table is inspected by PSC. Section 1 (introduction and ship particulars) is not in Regulation 37.1 itself but is required by the guidelines as the administrative frame for the other four elements.

Four-section SOPEP structure

Every approved SOPEP follows the same four-section structure. The structure is the architecture of the response: a Port State Control inspector who has read one SOPEP can navigate any other in under thirty seconds because the section numbers are constant.

Section 1: Introduction. The administrative and descriptive material. Ship particulars, the regulatory basis, the approval stamp, the language of the plan, and the table of revisions.

Section 2: Reporting requirements. When to report. The triggers for a Regulation 37 incident report, the format of the report, the content of the report, and the destinations of the report.

Section 3: Steps to control discharge. What to do. The shipboard response actions, organised by spill scenario: bunker overflow at the manifold, hull damage from grounding, hull damage from collision, fire-related spill, structural failure of a fuel tank.

Section 4: National and local contacts list. Whom to call. The coastal-State contacts for every region the ship trades into, the flag-State contact, the company contact, and the contact for the P&I club or other liability insurer.

A fifth element, the appendices, carries supporting material: a sample report form, the public-transport telephone codes, ship drawings showing fuel-tank locations and pumping arrangements, the SOPEP equipment list and its stowage plan, and the drill-and-exercise log. The appendices are part of the approved plan and are inspected at the same level of scrutiny as the four numbered sections.

Section 1: Introduction

Section 1 carries the descriptive material that frames the plan. It is read once when the plan is opened on board, and then referred to only at PSC inspection or IOPP renewal survey.

The mandatory content of Section 1 includes the ship’s name, IMO number, gross tonnage, deadweight, principal dimensions, hull type, cargo type, and year of build, together with the company as defined in the ISM Code, the flag State, and the Recognised Organisation that performed the IOPP survey.

Section 1 also carries the regulatory basis: a statement that the plan is prepared under MARPOL Annex I Regulation 37 and MEPC.54(32) as amended by MEPC.86(44), with a reference to MEPC.85(44) where the plan is a combined SMPEP/SOPEP. The approval stamp of the flag-State Administration or its Recognised Organisation appears on a dedicated approval page with the date of approval and a unique plan reference number.

The table of revisions is the part of Section 1 most often inspected. Every revision is logged with a date, brief description, and master’s signature. PSC inspectors compare revision-log dates against crew changes, port-State changes, and contact-list amendments to verify that the plan is being maintained.

Section 2: Reporting requirements

Section 2 is the most operationally important part of the plan. It tells the master when a report must be made and to whom.

The reporting trigger is set by Article 8 and Protocol I of MARPOL: the master of any ship involved in an incident shall report the particulars without delay to the nearest coastal State and to the flag State. Without delay is interpreted as immediately upon discovery, with one hour as the operational best-practice ceiling.

The five triggers for a SOPEP report are:

• A discharge or probable discharge resulting from damage to the ship or its equipment.
• A discharge during operations that exceeds the permissible quantity (the Regulation 15 fifteen-ppm ceiling, or equivalent threshold for tanker cargo discharges).
• A discharge during the transfer of oil to or from the ship.
• The presence of oil on the sea surface or shoreline that the crew has reason to believe came from the ship.
• An event involving probable damage to the ship that, if not addressed, would result in such a discharge.

The report follows the IMO Standard Report Format in MEPC.92(45), structured under fixed alphabetical designators (A through X) covering date and time, position, course and speed, weather, ship particulars, master’s name, type and quantity of oil, cause, actions taken, and assistance required.

The destinations are the nearest coastal-State authority (typically a Maritime Rescue Co-ordination Centre or national pollution-response authority) and the flag State. Both contacts appear in Section 4. Section 2 also requires follow-up reports as the situation develops and a final report when the incident is concluded.

Section 3: Steps to control discharge

Section 3 tells the crew what to do once the report has been made. It is organised by spill scenario, with a short flowchart for each scenario and a longer narrative procedure beneath it.

The standard scenarios required by MEPC.54(32) as amended by MEPC.86(44) are operational spills (bunker manifold overflow, internal-transfer overflow, oil filtering equipment failure, sample-cooler leak, hose burst, valve mis-alignment) and casualty spills (grounding, collision, fire and explosion, hull failure, listing or capsizing).

Each scenario has a fixed structure. First, the immediate actions by the watch officer: sound the alarm, stop the cargo or bunkering operation, close valves, mobilise the response team. Second, the assessment by the senior officer on scene: source identified, estimated rate of leak, total volume at risk. Third, the containment actions: deployment of oil residue tank emergency-transfer pumps, SOPEP boom around the manifold, sorbent pads on deck and alongside, ship-handling to reduce list and hydrostatic head. Fourth, the consequential actions: ballast adjustment, internal transfer away from the damaged tank, jettison only with coastal-State concurrence.

Section 3 must also address the priorities the master applies when scenarios overlap. The MEPC.54(32) Guidelines set the priorities as: (1) safety of life; (2) safety of the ship; (3) prevention or minimisation of pollution. The hierarchy is critical because some pollution-control actions, such as opening a valve to transfer fuel out of a damaged tank in heavy weather, may themselves be hazardous to life or structure.

For oil tankers, Section 3 also addresses cargo-specific actions: emergency cargo-tank pressure release, emergency inert-gas operation, segregation of damaged tanks from the cargo system, and for ships fitted with crude oil washing, emergency COW shut-down.

Section 4: National and local contacts list

Section 4 is the part of the plan that ages fastest. Coastal-State contact numbers change, embassies relocate, P&I correspondents reorganise, and a list that is six months out of date may give the master a wrong number at the worst moment of his career.

The mandatory content of Section 4 includes contact numbers (telephone, telex, fax, email, Inmarsat C terminal address where applicable) for: the nearest coastal-State pollution-response authority for every region the ship trades into; the flag-State Administration; the ship’s owner and the ISM Code Company; the Designated Person Ashore (DPA); the P&I club or other pollution-liability insurer; the salvage-services contractor under any pre-arranged contract (Lloyd’s Open Form or comparable); and the local agent at every port the ship calls into routinely.

The IMO maintains the master list of national pollution-response contacts in a publication updated annually and circulated by MEPC circular. Most flag States require the SOPEP to be updated against the latest IMO list at least once per year.

The contacts list is divided geographically by region (Mediterranean Sea, Baltic Sea, North Sea, North-East Atlantic, US Coast Guard Districts, Caribbean, West Africa, Indian Ocean, South-East Asia, Far East, Australia and New Zealand, Arctic) and within each region by national authority. The DPA’s number appears at the top of every regional sub-list because the DPA is the constant call regardless of where the ship is.

Combined SMPEP/SOPEP plan under MEPC.85(44)

A ship that carries noxious liquid substances under Annex II needs an emergency plan under both Annex I (for oil) and Annex II Regulation 17 (for NLS). MEPC.85(44), adopted on 13 March 2000, permits the two plans to be combined into a single Shipboard Marine Pollution Emergency Plan (SMPEP), often referred to as a combined SMPEP/SOPEP. MEPC.85(44) and MEPC.86(44) were adopted at the same 44th MEPC session; they address different instruments (the combined SMPEP and the amended SOPEP guidelines respectively) and must not be confused with each other.

The combined plan retains the four-section structure but expands each section to address both pollutant categories. Section 2 reporting addresses both the Annex I oil-spill triggers and the Annex II NLS-spill triggers (the latter using the GESAMP Hazard Profile categories X, Y, Z, OS to drive the response level). Section 3 response procedures add NLS-specific scenarios: cargo-tank rupture for a Category X NLS, vapour release from a heated cargo, reaction between incompatible cargoes in adjacent tanks. Section 4 contacts add NLS-specific national authorities where they are distinct from the oil-spill authority.

The combined plan is mandatory for every chemical tanker certified to carry NLS under Annex II, which captures every IBC-Code-certificated chemical tanker. Product tankers that occasionally carry biofuels classified as NLS Category Y must also carry a combined plan. Pure crude-oil tankers and clean-product tankers that never carry NLS retain the SOPEP-only plan.

The post-2010 expansion of the IBC Code to cover bio-fuels and the post-2015 expansion to cover renewable fuel feedstocks have pushed many former product tankers into the combined-plan category. For new builds the combined SMPEP/SOPEP is now the default in the chemical-tanker fleet.

Language requirement and translation

MEPC.54(32) paragraph 1.4, as confirmed in the MEPC.86(44) amendment text, requires that the SOPEP be in the working language of the master and senior officers. The intent is operational: in the first sixty seconds of a spill the duty officer must be able to read the procedure without translation lag.

Where the working language is not English, French, or Spanish, the plan must include a summary in one of those three languages. The summary covers Section 2 reporting and Section 4 contacts, the two parts a foreign PSC inspector or coastal-State responder needs to read.

In practice, the working-language and English-summary structure produces a bilingual plan. A Greek-flag ship’s plan is in Greek with an English summary; a Chinese-flag ship’s plan is in Mandarin with an English summary; a Russian-flag ship’s plan is in Russian with an English summary.

The translation must be exact. PSC inspectors are entitled to challenge a translation that omits or weakens a procedure. A 2018 Paris MoU detention case at Rotterdam involved an SOPEP whose Russian-language original required the master to notify the Coast Guard within thirty minutes but whose English summary translated the requirement as as soon as practicable. The detention was upheld on the grounds that the inconsistency rendered the plan defective.

Master, Chief Officer, Chief Engineer responsibilities

The plan must allocate response responsibilities to specific shipboard ranks. MEPC.54(32) as amended by MEPC.86(44) does not prescribe a fixed allocation, but every flag-State approval examines the allocation against the ship’s manning certificate and the ISM Code’s shore-and-ship safety-management structure.

The Master has overall command of the response. He decides the priorities under the MEPC.54(32) hierarchy (life, ship, pollution), authorises the report under Section 2, signs the report, communicates with the coastal State and the company DPA, and decides whether to enter or remain in port, anchor, or proceed to a place of refuge. He has authority under SOLAS Regulation V/34 to override commercial pressures from the charterer or operator. The master’s authority is the single most important element of the plan; the SOPEP is operative only if the master’s authority is unambiguous.

The Chief Officer has on-deck command of the response on cargo-related and deck-related spills. On a tanker he commands the cargo-deck response: closing manifold valves, deploying booms, segregating damaged tanks, supervising the deployment of oil discharge monitoring records of the event. On a non-tanker his role focuses on deck spills and on the use of mooring lines for ship-handling.

The Chief Engineer has on-deck command of the response on machinery-space spills. He commands the engine-room response: stopping bunker transfers, isolating the oil filtering equipment, re-aligning fuel-oil systems to transfer fuel out of damaged tanks, operating the emergency fire pump if the spill threatens engine-room safety, and maintaining the propulsion plant for whatever ship-handling actions the master orders.

The Officer of the Watch has the immediate-alarm function: he activates the SOPEP by calling the master and starting the on-board contact chain. The Bosun or Cargo Foreman commands the deck-rating team that physically deploys boom, sorbent pads, and emergency pumps. For large complex ships the SOPEP may include a dedicated Pollution Response Officer (often the Second Officer) whose sole role during the response is to maintain the timeline log and capture evidence.

Periodic drill: quarterly per ISM Code Section 8

The SOPEP itself must be exercised, or it remains only a paper plan. The exercise requirement is set by the ISM Code Section 8 (Emergency Preparedness) and by paragraph 1.5 of MEPC.54(32).

The minimum frequency is quarterly. Most flag States and most classification-society SMS templates require an SOPEP drill at least once every three months, which yields the relation:

The drill must exercise the full plan, not merely a single sub-element. A typical quarterly cycle rotates: Q1 bunker-manifold overflow; Q2 hull damage from grounding; Q3 collision with fire; Q4 internal-transfer overflow with a coastal-State communication exercise. Chemical tankers add a separate SMPEP/SOPEP combined-plan drill.

Each drill is logged with the date, scenario, participants, elapsed time from alarm to first report, elapsed time from alarm to first containment measure, and any shortcomings identified. The log is signed off by the master and forwarded to the company for the next ISM internal audit.

The quarterly drill requirement is rigorously inspected. An empty or back-dated drill log is among the most common SOPEP-related detention grounds in the Paris MoU and Tokyo MoU databases. A 2022 Tokyo MoU detention at Yokohama recorded a Greek-flag bulker whose drill log showed identical entries for four consecutive quarters: the inspector read the pattern as a forged log and detained the ship until a live drill was conducted under his observation.

Role of the Designated Person Ashore (DPA)

The DPA is the single point of contact between the ship and the company’s senior management on safety and pollution matters. The role was created by the ISM Code in 1994 and is referenced in every modern SOPEP.

In the SOPEP context the DPA has three functions. First, the DPA is the company’s twenty-four-hour duty contact, with the mobile number at the top of every Section 4 regional sub-list. Second, the DPA mobilises the company’s shore-side response: salvage contractor, P&I club, pollution-response contractor, legal counsel, and senior management. Third, the DPA has direct access to the company’s highest level of management without being filtered through operations; this independence is what makes the DPA effective in incidents that might otherwise be delayed by commercial considerations.

For the DPA to function, the SOPEP must show the DPA’s name, twenty-four-hour mobile number, deputy’s name and number, and office number and email. PSC inspectors test the DPA contact at random by calling the listed number during inspection. A DPA contact that goes to voicemail, rings unanswered, or produces an out-of-service tone is a recurring deficiency in PSC databases.

Reporting under SOLAS Reg V/31 and Annex I Reg 37

Reporting in a pollution incident runs in parallel under two regimes: the SOLAS distress-and-danger framework and the MARPOL pollution framework. The SOPEP integrates both.

SOLAS Regulation V/31 (formerly V/2) requires the master of any ship that encounters dangerous ice, derelicts, tropical storms, or any other direct danger to navigation, including a hazard from a casualty, to communicate the information to ships in the vicinity and to the nearest coastal-State authority. A pollution incident that involves a structural casualty triggers V/31, and the master sends a danger message under the SOLAS framework to warn ships in the vicinity that the casualty exists.

MARPOL Article 8 and Annex I Regulation 37 require the master to send a pollution-incident report under MEPC.92(45) standard format to the nearest coastal-State pollution authority and to the flag State. The pollution report is in addition to, not instead of, the SOLAS danger message.

In practice the two reports are sent within minutes of each other through the same communication medium (Inmarsat C, satellite voice, MF/HF radio). The SOPEP Section 2 procedure shows the master how to send both: the SOLAS danger message first because it warns vessels in the vicinity (an operational safety priority), then the MARPOL pollution report (an environmental priority). Where the situation involves loss of life or major casualty, an MOB or distress message under SOLAS Regulation IV/8 takes precedence over both.

The operational best-practice ceiling for the first report is one hour from incident:

A delay beyond one hour without documented operational justification (loss of communications, life-safety priority) is treated by most coastal-State authorities as an aggravating factor in any subsequent prosecution under their domestic pollution legislation.

SOPEP equipment list

The SOPEP equipment list is the inventory of pollution-response gear carried on board. It is an appendix to the plan and is inspected line by line at PSC boardings.

The standard equipment list, derived from MEPC.54(32) as amended by MEPC.86(44) and as amplified by class-society guidance, includes:

• Oil booms: floating barriers to contain a spill alongside the ship, typically 100 to 200 metres on a Panamax tanker, stowed on a dedicated reel near the manifold.
• Sorbent pads, rolls, and sausages: non-woven polypropylene material stowed in a SOPEP locker near the manifold and in the engine room.
• Dispersants: chemical agents used (only with coastal-State authorisation) to break up surface oil.
• Transfer pumps: air-driven or electric pumps to transfer recovered oil to a receiving tank or barge.
• Non-sparking tools: hammers, wrenches, and screwdrivers in beryllium-copper or aluminium-bronze alloy for use on deck where flammable vapour may be present.
• Personal protective equipment: oil-resistant suits, gloves, boots, goggles, and face shields.
• Self-contained breathing apparatus (SCBA): two sets minimum, with spare cylinders.
• Communication equipment: portable VHF radios separate from the bridge VHF.
• Lighting: portable explosion-proof torches and floodlights for night response.
• Drainage plugs and rags: for plugging deck scuppers to prevent on-deck oil from running over the side.

The equipment list is reconciled at PSC inspection against the actual gear in the SOPEP locker. A mismatch (boom listed but not present, sorbent pads listed at 200 kg but only 50 kg present, SCBA listed but cylinder out of test) is a frequent deficiency in the Paris MoU and Tokyo MoU databases.

2025 amendments: alternative-fuel spill reporting

The 2024 IGF Code amendments and the 2025 consolidated MARPOL edition extend the SOPEP reporting logic to spills of alternative marine fuels.

Methanol-fuelled ships already operate under the IGF Code Part A-1 chapter on low-flashpoint fuels. A methanol spill is not an oil spill in the strict Annex I sense (methanol is an alcohol, not a hydrocarbon, and is fully miscible in water), but the operational hazard pattern (toxicity, flammability, vapour cloud) is comparable. The 2025 amendments require that the SOPEP on a methanol-fuelled ship include a methanol-spill scenario in Section 3 and methanol-fire-protection contacts in Section 4.

Ammonia-fuelled ships face a more demanding reporting picture. Anhydrous ammonia is acutely toxic by inhalation and is not covered by Annex I. The 2025 amendments require an ammonia-release scenario in Section 3 with the response priorities reversed from oil: vapour control and personnel evacuation take priority over containment because the dominant risk is inhalation, not water pollution. The reporting threshold is lower than for oil, and the coastal-State authorities to be notified are the chemical-spill authorities (often a separate national agency from the oil-spill authority).

The post-2025 SOPEP on a dual-fuel ship is therefore three plans bundled in one document: the Annex I oil plan, the methanol plan (where applicable), and the ammonia plan (where applicable). Flag States have begun to refer to this combined document as the Marine Pollution and Hazardous Release Plan or MPHRP, though MARPOL’s terminology remains SOPEP.

Relationship to OPRC 1990 and OPRC-HNS Protocol

The SOPEP is the shipboard half of a two-half regime. The shore half is built by the OPRC Convention 1990 and the OPRC-HNS Protocol.

OPRC 1990 (the International Convention on Oil Pollution Preparedness, Response and Co-operation) entered into force on 13 May 1995. It requires every Party State to establish a national pollution-response system, designate competent authorities, maintain a National Contingency Plan, pre-position response equipment at strategic ports, and operate a twenty-four-hour pollution-incident reception centre. The shipboard SOPEP report under Annex I Regulation 37 is delivered into the OPRC reception centre, and the OPRC system delivers the shore response that the SOPEP cannot provide on its own.

The OPRC-HNS Protocol 2000 extends the OPRC architecture to hazardous and noxious substances, paralleling the way MEPC.85(44) extended the SOPEP into the SMPEP. The Protocol entered into force on 14 June 2007.

The shipboard-shore interaction is set by OPRC Article 4. When the master sends his Annex I Regulation 37 report to the nearest coastal-State authority, that authority is the OPRC-designated reception point, and the National Contingency Plan governs the shore response.

Tier 1 oil spills (small, contained, recoverable by the ship’s own equipment) are handled by the SOPEP alone. Tier 2 spills (larger, requiring local authority assistance) trigger the OPRC port-State response. Tier 3 spills (major, requiring international assistance) trigger the OPRC inter-State framework, including the Regional Marine Pollution Emergency Response Centre network (REMPEC for the Mediterranean, Bonn Agreement for the North Sea, Helsinki Convention for the Baltic).

Relationship to ISM Code Element 7-8

The SOPEP integrates with the ISM Code at two specific elements.

ISM Code Element 7 (shipboard operations) requires the company to establish procedures for key shipboard operations concerning the safety of the ship and the prevention of pollution. The SMS cross-references the SOPEP at every operational task that could generate a pollution incident: bunkering, internal transfers, crude oil washing, tank cleaning, oily-water-separator operation, and the Oil Record Book entry workflow. If the SOPEP procedure conflicts with the SMS procedure, the SMS must be amended, not the SOPEP, because the SOPEP carries flag-State approval and the SMS does not.

ISM Code Element 8 (emergency preparedness) requires the company to establish procedures to identify, describe, and respond to potential emergency situations. Element 8 is the source of the quarterly drill requirement; the drill log forms part of the SMS audit trail.

The integration of the SOPEP with Elements 7 and 8 is the reason both the Document of Compliance (DOC) audit at the company office and the Safety Management Certificate (SMC) audit on board examine SOPEP currency. A SOPEP that is in date but not embedded in the SMS is grounds for a major non-conformity, as is an SMS that does not reference the SOPEP at the operational tasks above.

Relationship to Bunkers Convention 2001 and CLC 1992 liability

The SOPEP is the operational document; the Bunkers Convention 2001 and the CLC 1992 are the financial-liability instruments that pay for the consequences of an incident the SOPEP could not prevent.

The CLC 1992 (Civil Liability for Oil Pollution Damage) imposes strict liability on the registered owner of a tanker for pollution damage caused by persistent oil cargo, with mandatory insurance backed by a CLC blue card. The 1992 Protocol raised the limits and brought them under the IOPC Funds. The CLC blue card is one of the certificates PSC inspectors verify alongside the SOPEP at every tanker boarding.

The Bunkers Convention 2001 extended the strict-liability regime to the bunker fuel of all ships, not just tanker cargo. It entered into force on 21 November 2008. Every ship of 1,000 GT and above must carry a Bunkers Convention blue card.

The SOPEP Section 4 contacts list must include the P&I club or other insurer that issues the blue cards, because that insurer mobilises the legal and financial response. A spill triggers the SOPEP; the SOPEP triggers the OPRC shore response; the shore response generates costs; the costs are claimed against the blue-card insurer (and ultimately the IOPC Funds for CLC oil cargo above the shipowner’s limit).

PSC inspection focus and IOPP renewal verification

Port State Control inspectors examine the SOPEP at every boarding. The standard inspection focus areas are derived from the Paris MoU and Tokyo MoU concentrated inspection campaigns and from the IMO Procedures for Port State Control (Resolution A.1185(33), 2023).

The five inspection focus areas are:

1. Latest SOPEP edition. The plan must reflect current revisions: the latest IMO contacts list (updated annually), the latest crew composition, the latest trading area, and the latest fuel type carried (relevant for dual-fuel ships post-2025).
2. Signed flag-State approval. The approval page must show the stamp and signature of the flag-State Administration or its Recognised Organisation, with a date that pre-dates the inspection.
3. Quarterly drill records. The drill log must show entries at intervals of no more than three months apart, with realistic scenarios, varied participants, and observations that change between drills (a sign that drills are being conducted live, not back-dated).
4. Equipment list reconciliation. The SOPEP locker contents must match the plan’s equipment-list appendix in line items and quantities. Tampered seals, missing items, and out-of-test SCBA are recurring deficiencies.
5. DPA contact verification. The inspector may call the DPA contact during inspection. The number must be answered by a live person identifying themselves as the DPA or DPA deputy and able to confirm the ship’s name and IMO number.

A SOPEP-related deficiency is recorded under MoU code 14605 (Paris MoU) or analogous codes in other regional MoUs. SOPEP deficiencies that are detention-grade are typically the absence of an approved plan, an outdated plan that does not reflect current trade, an empty drill log, or a missing equipment list.

The IOPP renewal survey, conducted at least every five years by the flag-State surveyor or its Recognised Organisation, verifies SOPEP currency as a survey item. The surveyor confirms that the plan is in date, that revisions have been entered correctly, that the drill log is current, that the equipment list matches the locker, and that the DPA contact has been called (a survey practice that has become standard since 2018). The IOPP certificate cannot be renewed if the SOPEP is materially defective.

Reporting thresholds and timeline

Three quantitative parameters govern the SOPEP regime, and a master can recite all three from memory. The gross-tonnage thresholds set who must carry a plan, the report time sets how fast the first message goes out, and the drill frequency sets how often the plan is exercised.

The carriage thresholds come straight from Regulation 37 paragraphs 1 and 2. A SOPEP is required when $GT \geq 400$ for any ship, or when $GT \geq 150$ for an oil tanker. The 400 GT limb covers cargo ships, bulkers, container ships, and gas carriers; the 150 GT limb pulls in small product tankers and bunker barges that fall below 400 GT but still carry oil cargo. Below those figures Annex I’s structural regime does not bite, though many flag States impose national-law equivalents on smaller craft.

The first-report ceiling derives from MARPOL Article 8 and Protocol I, which require the master to report without delay and, in the words of Protocol I, if not earlier, immediately upon discovery. The number itself, $T_{\text{report}} \leq 1 \text{ hour}$ from the incident, is not in the treaty text. It is the operational benchmark every major flag State and every classification-society SMS template adopts as the maximum reasonable elapsed time given satellite-communications availability. US Coast Guard prosecutors use the same one-hour mark to assess delay aggravation under 33 USC 1321, and EU enforcement authorities apply it under Directive 2005/35/EC. A delay past one hour without documented justification (loss of communications, a life-safety priority) is treated as an aggravating factor in any subsequent prosecution.

The drill frequency is set by ISM Code Element 8 and paragraph 1.5 of MEPC.54(32). The company must run a programme of drills and exercises to prepare for emergency action; the flag-State Administration sets the minimum in the SMS approval, and almost every flag State takes the IACS unified position that quarterly is the floor compatible with effective preparedness. That gives the working relation $N_{\text{drills,annual}} \geq 4$. The regulatory floor is four; the operational target on well-managed ships is six to eight drills a year, one every six to eight weeks. A combined SMPEP/SOPEP exercises both halves in the rotation, often by alternating the underlying scenario between an Annex I oil spill and an Annex II noxious-liquid-substance spill.

The thresholds assume a self-propelled commercial vessel within Annex I scope. Government-owned ships on non-commercial service and warships are exempt under Article 3(3). Fixed and floating platforms fall under Regulation 39 and carry their own emergency-plan requirements that parallel the SOPEP rather than duplicate it.

SOPEP scope and the four-section architecture in numbers

The four-section structure described above is what a PSC inspector navigates, and the numbers attached to each section are what gets checked. Section 1 carries the ship particulars and the dated revision table. Section 2 carries the five reporting triggers and the MEPC.92(45) alphabetical report format (designators A through X). Section 3 carries the response procedures, structured around the MEPC.54(32) priority hierarchy: (1) safety of life; (2) safety of the ship; (3) prevention or minimisation of pollution. Section 4 carries the regional contacts list, with the DPA’s twenty-four-hour mobile at the head of every regional sub-list and an annual update against the IMO master list as the regulatory minimum.

The appendices carry the SOPEP equipment list, and that list is reconciled line by line at every boarding. A Panamax tanker stows 100 to 200 metres of oil boom on a dedicated reel near the manifold, two SCBA sets minimum with spare cylinders, sorbent pads and rolls in a locker by the manifold and in the engine room, air-driven or electric transfer pumps, non-sparking beryllium-copper or aluminium-bronze tools, and explosion-proof lighting. A mismatch between the listed quantity and the locker contents (boom listed but absent, sorbent listed at 200 kg but only 50 kg present, an SCBA cylinder out of test) is a recurring deficiency in the Paris MoU and Tokyo MoU databases.

Worked example: an Aframax bunker overflow at Rotterdam

Consider a 75,000 DWT Aframax crude oil tanker on the Persian Gulf to Rotterdam route, measured at 42,500 GT. The ship sits above both thresholds (400 GT for any ship, 150 GT for an oil tanker), so a SOPEP is mandatory. It carries crude oil only, so the plan is SOPEP-only, not a combined SMPEP/SOPEP.

The plan is in English, the working language of the senior officers under a typical open-registry flag with multinational manning. The contacts list covers eight regions: the Persian Gulf, the Suez Canal Authority, the Mediterranean (REMPEC), the Strait of Gibraltar, the Bay of Biscay, the English Channel (MCA UK and CROSS France), the North Sea (Bonn Agreement parties), and the Rotterdam port authority. The DPA contact is the company’s HSEQ Manager, with a twenty-four-hour mobile listed at the head of every regional sub-list.

The quarterly drill rotation runs: Q1 manifold overflow at Ras Tanura; Q2 grounding at the Strait of Hormuz; Q3 collision-and-fire in the Mediterranean; Q4 internal-transfer overflow at Rotterdam. Four drills, logged at intervals of no more than three months, satisfy $N_{\text{drills,annual}} \geq 4$.

Now the incident. A bunker overflow occurs at Rotterdam at 14:32 local. The duty deck officer activates the SOPEP at 14:33; the chief officer stops the bunker at 14:34. The first report in MEPC.92(45) format reaches the Dutch Coast Guard at 14:48, sixteen minutes from the incident, well inside the one-hour ceiling. The same report goes in parallel to the flag State, the company DPA, the P&I club, and the local agent. Sorbent boom containment is in place at 14:55. Estimated quantity spilled: 0.4 cubic metres. The event is logged in the Oil Record Book Part I as a Code G accidental discharge. The timeline (alarm at +1 minute, source isolated at +2 minutes, first report at +16 minutes, containment at +23 minutes) is exactly the kind of record a PSC inspector reads as evidence that the plan works in practice, not just on paper.

Common SOPEP defects

Seven defect patterns account for most SOPEP findings in the regional MoU databases, and each maps to a specific section of the plan.

Out-of-date contacts list. The single most common SOPEP defect, and a Section 4 problem. Coastal-State numbers change, embassies relocate, and P&I correspondents reorganise; a list six months old can hand the master a dead number at the worst moment of the incident. Annual update against the IMO master list is the regulatory minimum.

Back-dated drill log. Identical entries across consecutive quarters, the same scenario, the same participants, the same elapsed times. The 2022 Tokyo MoU detention at Yokohama turned on exactly this: four identical quarterly entries read as a forged log, and the inspector held the ship until a live drill was run under observation.

Equipment-list mismatch. Items listed but absent from the locker, items present but unlisted, quantities below the listed minimum. Reconciliation is a five-minute task at every monthly safety round, and it is consistently neglected.

DPA contact that does not answer. A DPA number that rings unanswered or drops to voicemail at three in the morning is a failure of the whole ISM Code architecture. A PSC inspector who places the test call and gets dead air will detain the ship.

Translation inconsistency. The working-language original and the English summary disagree on a procedure or a threshold. The Rotterdam case from 2018, where the Russian original required notification within thirty minutes but the English summary read as soon as practicable, shows how an internal contradiction renders the plan defective on its face.

Outdated regulatory references. A plan that still cites the pre-2004 Regulation 26 numbering, or a 1990s contacts format, is treated as not maintained even where the operative content is correct.

Missing alternative-fuel scenarios on dual-fuel ships. A methanol-fuelled ship whose SOPEP omits methanol scenarios, or an ammonia-fuelled ship whose plan omits ammonia release, breaches the 2025 amendments. The legal basis is layered: Regulation 37 in the consolidated 2025 edition for the carriage duty, MEPC.54(32) as amended by MEPC.86(44) for content, MEPC.85(44) for the combined-plan extension, MEPC.92(45) for the report format, ISM Code Sections 7 and 8 (mandatory under SOLAS Chapter IX) for the SMS integration, OPRC 1990 and the OPRC-HNS Protocol for the shore response, and CLC 1992 with the Bunkers Convention 2001 for the financial liability behind the Section 4 insurer contacts.

Limitations

The figures and procedures above are accurate for the typical case, but a practitioner relies on them with several caveats firmly in mind. A SOPEP is a planning document, and a plan is only ever a model of the casualty it anticipates.

The first limitation is the SOPEP versus SMPEP versus VRP overlap. A single ship trading to the United States may have to satisfy three regimes at once: the Annex I SOPEP, a combined SMPEP under MEPC.85(44) if it carries noxious liquid substances, and a US Vessel Response Plan under 33 CFR Part 155 with named Qualified Individuals and a contracted Oil Spill Removal Organisation. The three plans use different reporting thresholds, different contact structures, and different drill records. A SOPEP that is fully compliant with Annex I can still leave the ship non-compliant in a US port if the VRP elements are missing, and the converse is also true. The single-document convenience of a combined plan does not erase the underlying distinctions, and treating them as interchangeable is a frequent error.

The second limitation is the drill-versus-reality gap. Four logged drills a year prove that the crew has rehearsed the procedure; they do not prove the crew can execute it under the conditions of a real casualty, at night, in heavy weather, with a reduced watch and a language barrier between ranks. The elapsed times recorded in a planned drill, where everyone knows the scenario in advance, systematically understate the times a real incident produces. The one-hour report ceiling is achievable in a drill almost every time and is missed more often than the logs suggest when a genuine grounding floods the bridge with competing priorities. A clean drill log is necessary but not sufficient evidence of preparedness.

The third limitation is contact-list staleness. Section 4 is the part of the plan that decays fastest, and the annual update cycle guarantees that for up to twelve months the listed numbers can lag the live ones. Coastal-State reception centres re-number, P&I correspondents merge, and agents change. The plan can be formally in date (updated within the last year against the IMO list) and still carry a number that was disconnected last week. The limitation is structural: no annual paper cycle keeps pace with real-time organisational change.

The fourth limitation is flag-State and coastal-State reporting differences. MARPOL Article 8 sets the duty to report to the nearest coastal State and the flag State, but the threshold for what must be reported, the format demanded, and the authority that receives it vary by jurisdiction. A spill that triggers a mandatory report in one coastal State may fall below another’s domestic threshold; a State that is not a Party to MARPOL or has not designated an OPRC Article 4 authority may have no functioning reception point at all. The SOPEP’s standard MEPC.92(45) format is a baseline, not a guarantee that the receiving State will act on it as the plan assumes.

The fifth limitation is the estimate caveat on every spill quantity. The 0.4 cubic metres in the worked example is an on-scene estimate, not a measurement; spill volumes are routinely estimated by sight, by tank-gauge difference, or by the area and thickness of the surface sheen, and those methods carry wide error bands. A volume reported in the first hour can be revised by an order of magnitude once shore assessment is complete. The reporting duty attaches to a probable discharge, so the master must often report before any reliable quantity is known. The numbers in a first report are working estimates, and any downstream use of them, for liability allocation or for response scaling, inherits that uncertainty. This is the central limitation of the whole regime: the SOPEP forces a fast decision on incomplete information, and speed is bought at the cost of precision.

See also

• MARPOL Annex I oil pollution prevention
• MARPOL Annex I Regulation 12: oil residue tanks
• MARPOL Annex I Regulation 14: oil filtering equipment
• MARPOL Annex I Regulation 15: discharge control
• MARPOL Annex I Regulation 17: Oil Record Book
• MARPOL Annex I Regulation 28: damage stability
• MARPOL Annex I Regulation 33: crude oil washing
• MARPOL Annex II noxious liquid substances
• MARPOL Convention
• OPRC 1990 and HNS Protocol
• Ammonia as marine fuel
• Methanol as marine fuel
• Calculators

Related calculators

• MARPOL Annex I/37 - Shipboard Oil Pollution Emergency Plan
• MARPOL Annex II/14 - Shipboard marine pollution plan NLS
• MARPOL Annex VI/18 - Fuel oil quality
• MARPOL Annex VI/16 - Shipboard incineration
• MARPOL Annex V/9 - Placards garbage management plan
• MARPOL Annex II/10 - International pollution prevention cert NLS
• MARPOL Annex I/4 - Oil discharge
• MARPOL Annex I/38 - Reception facilities oil