SEEMP Part III: New Fuel Data Collection Requirements for 2026

Fuel data collection is no longer optional paperwork. MARPOL Annex VI now requires vessels of 5,000GT and above to collect and report detailed fuel consumption data annually — and the requirements are expanding. For superyachts approaching or exceeding that threshold, SEEMP Part III is the document that ties it all together.

Even if your yacht falls below 5,000GT, understanding these requirements matters. Flag states are increasingly applying energy efficiency standards to smaller vessels, and the Carbon Intensity Indicator (CII) rating system is shaping the future of maritime environmental regulation. The direction of travel is clear: what applies to large vessels today will reach yachts tomorrow.

Who Needs This?

• Owners and operators of yachts of 5,000GT and above (mandatory)
• Owners and operators of yachts of 400GT and above (SEEMP Part I is already mandatory; understanding Part III prepares you for future requirements)
• Chief engineers managing fuel data recording and reporting
• DPAs and management companies responsible for regulatory compliance
• New build teams specifying fuel monitoring and data collection systems

Understanding the Three Parts of SEEMP

The Ship Energy Efficiency Management Plan has evolved from a single document into a three-part framework under MARPOL Annex VI:

Part I is the operational plan that has been required since 2013. Part II was introduced in 2019 and establishes how you collect fuel data. Part III, introduced through MEPC 76 amendments effective from 1 January 2023, adds the CII rating system and requires a plan to achieve and maintain your required carbon intensity.

The Data Collection System (DCS)

MARPOL Annex VI Regulation 27 requires vessels of 5,000GT and above to collect and report fuel oil consumption data. This is the Data Collection System, and SEEMP Part II defines your methodology for collecting it.

What Data to Collect

The DCS requires the following data to be collected for each calendar year:

Fuel consumption must be broken down by fuel type and recorded using one of the following methods specified in your SEEMP Part II:

1. BDN and tank soundings — Most common method for yachts. Use Bunker Delivery Notes for quantities received and tank soundings for consumption calculations.
2. Bunker fuel tank monitoring — Automated flow meters on fuel service systems
3. Flow meters — Direct measurement of fuel consumed by engines and boilers
4. Direct CO2 emission measurement — Continuous emissions monitoring (rare on yachts)

CII Ratings Explained

The Carbon Intensity Indicator (CII) rates a vessel’s operational carbon intensity on a scale from A to E.

Operational CII is calculated as:

Attained CII = Total CO2 emissions / (DWT x Distance travelled)

The result is compared against reference values that tighten annually through reduction factors set by the IMO:

A vessel rated D for three consecutive years, or rated E in any single year, must submit a revised SEEMP Part III with a corrective action plan demonstrating how it will achieve at least a C rating.

CII Reduction Factors

The required CII tightens each year. The reduction factors relative to the 2019 baseline are:

Post-2026 reduction factors are under review at MEPC and are expected to increase further as part of the IMO’s revised GHG strategy targeting net-zero by 2050.

Reporting Timelines

The annual cycle works as follows:

1. 1 January — 31 December: Collect fuel consumption, distance, and hours underway data throughout the calendar year
2. By 31 March (following year): Submit collected data to your flag administration or Recognised Organisation (RO)
3. Verification: The RO verifies the data and issues a Statement of Compliance (SoC)
4. IMO submission: The flag administration reports verified data to the IMO Ship Fuel Oil Consumption Database
5. CII rating issued: Based on the verified data, the vessel receives its annual CII rating

EEOI Calculations

The Energy Efficiency Operational Indicator (EEOI) is a voluntary monitoring tool defined in MEPC.1/Circ.684. While not mandatory, it provides a useful voyage-by-voyage measure of carbon intensity:

EEOI = CO2 emissions / (cargo carried x distance)

For superyachts, “cargo carried” is typically replaced by GT or DWT as a proxy, since yachts do not carry cargo in the traditional sense. The EEOI is useful for tracking trends over time, comparing performance between voyages, and identifying operational changes that improve efficiency.

Recording EEOI data on a per-voyage basis in your SEEMP Part I demonstrates proactive energy management — something auditors and flag states view favourably.

Practical Recording Procedures

Here is how to set up effective fuel data collection on board:

1. Designate responsibility. Assign fuel data collection to the Chief Engineer or Second Engineer. Ensure this responsibility is documented in your SMS.

2. Standardise the recording format. Create a monthly fuel data collection sheet that captures: daily fuel oil consumption by type and by consumer (main engines, generators, boilers), daily tank soundings, daily noon position and distance run, and hours underway.

3. Record bunkering events. Log every bunkering with date, port, supplier, fuel type, quantity received, sulphur content, and BDN reference number. Retain BDNs on board.

4. Conduct regular tank soundings. Take soundings at a consistent time each day (typically at noon or midnight). Record tank levels, temperatures, and calculated volumes. Use the vessel’s tank calibration tables.

5. Calculate monthly consumption. At the end of each month, calculate total consumption by fuel type using the formula: Opening stock + Bunkers received - Closing stock = Consumption.

6. Track distance and hours. Extract daily distance run and hours underway from the bridge logbook or voyage data recorder. Reconcile with the Chief Officer’s records monthly.

7. Compile the annual report. By mid-January, consolidate the 12 monthly records into the annual data submission format required by your flag state or RO.

8. Submit for verification. Forward the compiled data to your classification society or flag administration for verification by the 31 March deadline.

Common Mistakes and Audit Findings

• Inconsistent measurement methods. If your SEEMP Part II says you use BDN and tank soundings but your engineer is using flow meter readings, that is a non-conformity. Use the method documented in your plan.
• Missing or incomplete daily records. Gaps in daily fuel logs undermine the integrity of your annual data. If a day is missed, note the reason and estimate the consumption with a documented methodology.
• Not accounting for fuel type correctly. Different fuels have different CO2 emission factors. HFO, MGO, and LNG produce different amounts of CO2 per tonne burned. Ensure you are applying the correct conversion factors from the IMO guidelines (MEPC.364(79)).
• Ignoring auxiliary consumption. Fuel burned by generators, boilers, and incinerators counts toward total consumption. Do not report only main engine fuel.
• No corrective action plan for D or E rating. If your CII calculation indicates a D or E trajectory, you must have a documented plan in SEEMP Part III showing how you will improve. Operational measures (slow steaming, route optimisation, shore power) should be specified with timelines.
• SEEMP not updated after system changes. If you refit engines, install a shore power connection, or change fuel type, update your SEEMP to reflect these changes.

How We Can Help

Our SEEMP template covers Parts I, II, and III in a single integrated document designed for superyachts. It includes pre-formatted fuel data collection sheets, CII calculation worksheets, EEOI tracking tables, and corrective action plan templates. Whether your yacht is above or below the 5,000GT threshold, the template provides a structured approach to energy efficiency management that satisfies flag state requirements and demonstrates best practice during audits.

Frequently Asked Questions

Does SEEMP Part III apply to yachts under 5,000GT?

Formally, SEEMP Part I is required under MARPOL Annex VI Regulation 22 for all vessels of 400GT and above. Parts II (Regulation 22A) and III (Regulation 26) apply to vessels of 5,000GT and above. Additionally, SEEMP Part III and the CII rating system currently apply only to specific ship types (bulk carriers, tankers, container ships, etc.) and do not apply to yachts. However, several flag states are encouraging voluntary compliance with Parts II and III for yachts between 400GT and 5,000GT, and future amendments may expand the scope. Implementing data collection now puts you ahead of the curve.

How is CII calculated for yachts that spend long periods at anchor?

This is a known issue with the CII framework. Yachts spend significantly more time at anchor or alongside than commercial vessels, meaning their distance-based CII can appear disproportionately poor. The IMO is reviewing correction factors for vessel types with non-standard operational profiles. In the meantime, document your operational profile clearly in SEEMP Part III and ensure your flag state understands the context of your CII rating.

What CO2 emission factors should I use?

Use the default emission factors specified in MEPC.364(79) and its subsequent amendments. The key values are: Diesel/Gas Oil (MGO/MDO) = 3.206 t-CO2/t-fuel, Light Fuel Oil (LFO) = 3.151, Heavy Fuel Oil (HFO) = 3.114, and LNG = 2.750. These factors are applied to your fuel consumption data when calculating total CO2 emissions for CII purposes.