Change Over Fuel (Fuel Oil Changeover ECA)
The fuel changeover procedure at the entry/exit of Emission Control Areas: timings and records that inspectors always check.
Operational Explanation
On entering an Emission Control Area (ECA) the ship must switch from fuel compliant with the global limit (0.50% sulphur m/m) to fuel with a sulphur content not exceeding 0.10% m/m (or use an equivalent abatement system, e.g. an approved scrubber).
May 2025 update: under Resolution MEPC.361(79) the entire Mediterranean Sea became a SECA (Sulphur Emission Control Area): from 1 May 2025 the changeover to 0.10% S fuel (or use of an equivalent scrubber) is mandatory for anyone transiting the Mediterranean too, not only in the historical ECAs.
2026 update: two new ECAs were designated (Canadian Arctic and the Norwegian Sea, Resolution MEPC.392(82), from 1 March 2026), adding to North America, the US Caribbean, the Baltic, the North Sea and the Mediterranean. For the full regulatory picture, see the MARPOL Annex VI topic.
Regulatory Reference
MARPOL Annex VI, Regulation 14 (sulphur limits) and Regulation 4 (equivalent methods, e.g. scrubbers). Global sulphur cap 0.50% m/m since 2020; ECA limit 0.10% m/m.
The provision this page rests on is Regulation 14.6. In the revised Annex VI (res. MEPC.328(76)) it reads: “Those ships using separate fuel oils to comply with paragraph 4 of this regulation and entering or leaving an emission control area set forth in paragraph 3 of this regulation shall carry a written procedure showing how the fuel oil changeover is to be done, allowing sufficient time for the fuel oil service system to be fully flushed of all fuel oils exceeding the applicable sulphur content specified in paragraph 4 of this regulation prior to entry into an emission control area. The volume of low sulphur fuel oils in each tank as well as the date, time and position of the ship when any fuel oil changeover operation is completed prior to the entry into an emission control area or commenced after exit from such an area shall be recorded in such logbook or electronic record book as prescribed by the Administration”.
Two obligations, and the second is the one people forget. The first is the written procedure, which must show how the changeover is performed and allow time for the service system to be fully flushed before entry. The second is the record, and it is not only date, time and position: it asks for the volume of low sulphur fuel oil in each tank. That is the figure that lets an inspector verify the changeover actually happened, and it is the one worked examples most often omit.
The same Regulation 14, at paragraph 14.7, carries the exemption for the first twelve months: “During the first 12 months immediately following entry into force of an amendment designating a specific emission control area under paragraph 3 of this regulation, ships operating in that emission control area are exempt from the requirements in paragraphs 4 and 6 of this regulation”. That is where the one-year gap between designating a new ECA and the 0.10% obligation comes from: it is not practice, it is written.
When compliant fuel cannot be found, Regulation 18.2 governs what the ship must do — and its paragraphs are almost always cited confusedly. 18.2.1 is the evidence paragraph: the authority is entitled to require from the ship a record of the actions taken and proof that it “attempted to purchase compliant fuel oil in accordance with its voyage plan and, if it was not made available where planned, that attempts were made to locate alternative sources”. 18.2.4 is the notification paragraph: “A ship shall notify its Administration and the competent authority of the relevant port of destination when it cannot purchase compliant fuel oil” — flag Administration and destination port authority, not one or the other. 18.2.5 closes the loop upwards: the Party notifies the Organization when a ship has presented evidence of non-availability.
18.2.2 is the paragraph that protects the ship, and it must be read as written: “The ship should not be required to deviate from its intended voyage or to delay unduly the voyage in order to achieve compliance”. It is a should, not a shall: a strong recommendation addressed to authorities, not an enforceable right of the ship. And 18.2.3 requires the authority to take into account all relevant circumstances and the evidence presented “including not taking control measures”.
The instrument through which the evidence is presented is the FONAR, Fuel Oil Non-Availability Report, whose standard format is Appendix 1 to resolution MEPC.320(74). It requires ship particulars, the voyage plan, documentary proof of purchase attempts with supplier contacts, details of the supply disruption, operational constraints, plans to bunker at subsequent ports and a list of FONARs submitted in the preceding twelve months. That last field is why a FONAR is not a repeatable formality: repetition is itself an element of the assessment.
Scope of Application
Ships that, in order to comply with the ECA sulphur limit, use separate fuel oils: these are the ships Regulation 14.6 asks for a written changeover procedure and the related records. The compliance method has to be settled first: a ship running continuously on a single already-compliant fuel performs no changeover, and a ship covered by an equivalent arrangement approved under Regulation 4 — scrubber, alternative fuels — follows that, not this procedure.
Procedure / How to Complete It
- Plan the changeover with sufficient lead time before the ECA boundary, allowing for the fuel's residence time in the lines and systems.
- Record the events Regulation 14.6 prescribes, which are not symmetrical: the volume of low-sulphur fuel oil in each tank, with the date, time and position of the ship when the changeover is completed before entry into the ECA and when it is commenced after exit. The record goes in the logbook or electronic record book prescribed by the Administration.
- Verify the changeover is completed before entering the ECA (not at the point of entry itself).
- On exiting the ECA, similarly record the changeover back to standard-sulphur fuel.
- For ships fitted with a scrubber, verify and record the system's correct operation as an alternative to changeover.
Practical Example
The position 50°45'N 001°30'W is not 46 miles from the North Sea ECA boundary: it is already inside the ECA, and well inside.
The sum is done from the definition, not by eye. The North Sea area referred to by Annex VI is the one in Annex V (res. MEPC.201(62)), and it includes “the English Channel and its approaches eastwards of longitude 5° W and northwards of latitude 48° 30' N”. The point 50°45'N 001°30'W satisfies both inequalities: it is east of 005°W and north of 48°30'N. At that latitude one degree of longitude is about 38 nautical miles, so from 005°W to 001°30'W there are over 130 miles of ECA already run.
Example entry, rewritten: "Changeover started 2026-08-03 at 04:00, position 49°20'N 006°10'W, about 45 miles from the 005°W meridian that bounds the North Sea ECA to the west; completed at 06:30, position 49°28'N 005°35'W, still outside the boundary. Volume of low sulphur fuel oil in each tank recorded. 0.10% S fuel confirmed by bunker analysis certificate."
What Typically Goes Wrong
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| Changeover started too late | Ship inside the ECA still running non-compliant fuel | Calculate line residence time and bring the operation forward |
| Incomplete record (position/quantity missing) | Annex VI PSC deficiency | Use a standard changeover form with all required fields |
| Bunker Delivery Note inconsistent with the fuel declared compliant | Dispute over fuel quality | Always keep the Bunker Delivery Note and the MARPOL sample |
| Procedures not updated after the Mediterranean SECA (1 May 2025) | Use of non-compliant fuel in an area now regulated | Update onboard procedures and bunker planning to include the Mediterranean among the SECAs |
| Using the FONAR as a permanent authorisation | The FONAR documents diligence but does not authorise continuing use of non-compliant fuel | Treat the FONAR as a documented, exceptional measure, not a recurring solution |
What the PSCO Checks
Operational Tips
- Always calculate the fuel's residence time in the lines before planning the changeover.
- Use a dedicated form (not just the generic engine log) to track the operation.
- Keep track of the calendar of new ECAs, and keep designation apart from the fuel obligation: Mediterranean from 1 May 2025; Canadian Arctic and Norwegian Sea designated from 1 March 2026, but with the 0.10% and PM limits applicable from 1 March 2027. A changeover brought forward by twelve months is a cost, not a precaution.
- If compliant fuel is not available in port, prepare a documented FONAR (Fuel Oil Non-Availability Report) to submit to the Administrations concerned.
Preparation checklist
Educational checklist. This summary supports learning and preparation only. It does not replace the vessel’s approved procedures, manuals, statutory documents, company SMS, or applicable official requirements. Completing it demonstrates neither compliance nor readiness for an inspection: it shows that a list has been read, not that the ship is in order. Always verify the current documents carried on board.
- Changeover planned with adequate lead time
- Complete record (date, time, position, quantity)
- Bunker Delivery Note and fuel sample retained
- Scrubber, if fitted, verified and recorded as an alternative
FAQ
Related Topics
Last substantive revision of this page: 28 August 2026 · page fingerprint 53806edd6617