SEEMP Part III & CII Compliance under MARPOL Annex VI
The Ship Energy Efficiency Management Plan (SEEMP) provides the operational framework through which ships improve and manage energy efficiency and carbon-intensity performance.
Under MARPOL Annex VI Regulation 26, applicable ships subject to the operational carbon intensity requirements are required to maintain the relevant SEEMP arrangements. Part III of the SEEMP is the Ship Operational Carbon Intensity Plan and is directly connected with the vessel's operational CII performance.
The current IMO framework is based on the 2024 Guidelines for the Development of a Ship Energy Efficiency Management Plan, adopted by MEPC.395(82), together with subsequent amendments adopted by the IMO Marine Environment Protection Committee.
SEEMP Part III is not simply a document kept on board for inspection. It establishes the vessel-specific methodology, implementation measures, monitoring arrangements, and corrective actions used to manage operational carbon intensity over time.
Scope of SEEMP Part III
SEEMP Part III is focused on the vessel's operational carbon intensity. It connects the ship's attained annual CII, required CII, operational rating, data-management arrangements, and measures intended to achieve the required performance.
Ship-Specific Plan
Part III is developed for the individual ship and records the arrangements used to manage and improve its operational carbon intensity.
CII Methodology
The plan provides information on the methodology used to calculate the vessel's attained annual operational CII and the data required for that calculation.
Required CII
The applicable required annual operational CII and the vessel's expected performance are incorporated into the carbon-intensity management framework.
CII Rating
The vessel's operational carbon-intensity performance is reflected through the applicable annual CII rating from A to E.
Implementation Plan
Part III identifies measures and actions intended to achieve the required operational carbon-intensity performance.
Monitoring
Relevant fuel-consumption, transport-work, operational, and other required data must be collected and managed consistently.
Corrective Action
Where corrective action is required, the SEEMP provides the framework for recording and implementing measures to improve the ship's carbon-intensity performance.
Review & Updating
The plan should be maintained and updated where required, including where voluntary modifications or necessary corrective actions are involved.
1. SEEMP Part III and the IMO CII Framework
The IMO's short-term greenhouse-gas reduction measures introduced the operational CII rating together with an enhanced SEEMP framework. For applicable ships, the attained annual operational CII is determined using the relevant operational data and is assessed against the required annual operational CII.
The resulting operational carbon-intensity performance is assigned a rating from A to E, with A representing the strongest performance level and E the lowest performance level.
The CII framework is therefore not limited to a calculation at the end of the reporting year. It requires the shipowner and technical management team to understand the vessel's operational performance and implement measures capable of maintaining or improving the required carbon-intensity level.
Main Elements of the CII Management Framework
- Required annual operational CII
- Attained annual operational CII
- Applicable CII calculation methodology
- Operational carbon-intensity rating
- Fuel-consumption and operational data
- Three-year performance and planning information
- Measures for improving carbon-intensity performance
- Corrective actions where required
2. Required and Attained Annual Operational CII
The CII framework compares the ship's attained annual operational CII with the applicable required annual operational CII. This comparison forms the basis for the vessel's operational carbon-intensity rating.
The applicable calculation depends on the ship type and the relevant CII methodology. The SEEMP Part III should explain how the required information is obtained and how the vessel's attained annual operational CII is calculated.
The plan should therefore be consistent with the vessel's actual operational data-management practices rather than functioning as a generic environmental policy document.
Required CII
The required annual operational CII establishes the applicable performance level against which the vessel's attained operational carbon intensity is assessed.
Attained CII
The attained annual operational CII represents the vessel's calculated operational carbon-intensity performance based on the applicable data and methodology.
Rating
The attained performance is used to determine the vessel's applicable annual operational carbon-intensity rating from A through E.
Performance Trend
Reviewing historical and projected performance helps the company identify whether operational measures are producing the required improvement.
3. Contents of the SEEMP Part III Plan
The SEEMP Part III should contain the information necessary to manage the vessel's operational carbon intensity in accordance with the applicable IMO requirements and guidelines.
The 2024 SEEMP Guidelines provide a structured framework for the ship operational carbon intensity plan, including the review and update log, required CII information, calculation methodology, implementation planning, and relevant data-quality arrangements.
Principal Documentation Areas
- Review and update log
- Ship identification and applicable CII information
- Required annual operational CII
- Attained annual operational CII and historical ratings
- Calculation methodology
- Required data and data sources
- Data collection and quality arrangements
- Three-year implementation plan
- Corrective actions where applicable
- Relevant supporting records and evidence
4. CII Data Collection & Data Quality
Reliable CII performance depends on reliable operational data. Errors in fuel-consumption records, distance travelled, transport-work information, voyage records, or other applicable parameters can affect the calculation of the attained annual operational CII.
SEEMP Part III should therefore describe how the required data are obtained, processed, checked, and used in the CII calculation.
Fuel Consumption
Fuel-consumption information should be consistent with the applicable IMO DCS arrangements and the data used for the vessel's operational carbon-intensity calculation.
Distance Travelled
Distance data should be recorded and controlled according to the applicable CII calculation methodology and reporting arrangements.
Transport Work
Where applicable, transport-work data and the relevant methodology should be properly identified and supported by appropriate records.
Data Verification
Internal checks should identify inconsistencies or missing information before the data are used for final CII assessment and reporting.
5. Three-Year CII Implementation Plan
SEEMP Part III includes a three-year implementation plan for managing the ship's operational carbon intensity. The plan should identify practical measures that can support the required performance over the applicable planning period.
The measures selected should be appropriate to the individual vessel, its trading pattern, operational profile, machinery, propulsion arrangement, commercial requirements, and available technical options.
Potential Operational Measures
- Voyage planning and optimization
- Weather routing where appropriate
- Speed and power optimization
- Main engine and auxiliary engine performance monitoring
- Hull and propeller condition management
- Propulsion-efficiency improvements
- Energy-management measures
- Fuel-consumption monitoring
- Operational procedures supporting efficient navigation
- Other technically and operationally suitable measures
6. CII Ratings & Corrective Action
The operational CII rating provides an annual indication of the vessel's carbon-intensity performance. The rating system uses categories from A to E.
Where the applicable IMO requirements trigger corrective action, the company must address the vessel's performance through an appropriate corrective-action process incorporated into the SEEMP framework.
IMO requirements provide that a ship rated D for three consecutive years, or E, is required to develop a plan of corrective actions demonstrating how the required index would be achieved.
Rating A
Indicates a high level of operational carbon-intensity performance within the applicable rating framework.
Rating B
Indicates performance above the level associated with the moderate reference category.
Rating C
Represents the moderate performance category within the applicable CII rating system.
Rating D
Indicates performance requiring attention, with consecutive D ratings potentially triggering corrective action requirements.
Rating E
Indicates the lowest performance category and triggers the applicable corrective-action requirements.
Corrective Action
Corrective measures should identify practical actions and demonstrate how the required operational carbon-intensity performance will be achieved.
7. SEEMP Part III Verification & Company Audits
SEEMP Part III is subject to verification arrangements established under the applicable MARPOL Annex VI framework and IMO guidelines. The IMO has issued specific guidelines concerning verification and company audits by the Administration of Part III of the SEEMP.
Verification is intended to assess whether the documented arrangements are consistent with the applicable requirements and whether the company has appropriate processes for managing the ship's operational carbon intensity.
The exact verification and certification arrangements depend on the applicable ship, Administration, recognized organization, and statutory framework. Owners and technical managers should therefore confirm the applicable requirements with the responsible Administration or recognized organization.
Areas That May Require Verification
- SEEMP Part III documentation
- CII calculation methodology
- Required and attained CII information
- Data collection and data-management procedures
- Three-year implementation plan
- Corrective-action arrangements where applicable
- Supporting operational records
- Company procedures related to CII management
8. SEEMP Part III Review & Updating
SEEMP Part III should be treated as a controlled operational document rather than a static file. Changes to the vessel's operational arrangements, CII performance, corrective actions, or other applicable circumstances may require the plan to be reviewed and updated.
The applicable IMO guidelines provide for updating Part III where voluntary modifications or necessary corrective actions are involved. The plan should remain consistent with the vessel's actual carbon-intensity management arrangements.
Annual Performance Review
Review the vessel's attained annual CII, applicable rating, historical performance, and operational trends.
Corrective Measures
Record and implement applicable corrective measures where the vessel's performance requires improvement.
Operational Changes
Consider relevant changes to the vessel's trading pattern, operational profile, machinery, or efficiency measures.
Document Control
Maintain revision history and supporting evidence so that the current SEEMP Part III remains traceable and consistent with the vessel's actual arrangements.
9. Relationship Between SEEMP Part II, Part III & CII
SEEMP is structured into different parts addressing different aspects of ship energy efficiency and operational carbon management.
SEEMP Part I
Provides the ship management plan for improving energy efficiency and establishing operational energy-efficiency practices.
SEEMP Part II
Addresses the ship fuel oil consumption data collection plan associated with the IMO Data Collection System.
SEEMP Part III
Provides the ship operational carbon intensity plan and establishes the vessel-specific framework for managing CII performance.
CII
Provides the operational carbon-intensity performance measure and annual rating associated with the applicable MARPOL Annex VI requirements.
These elements should be managed as connected parts of the vessel's environmental and energy-efficiency management system, while maintaining the specific documentation and verification requirements applicable to each component.
10. Preparing a Vessel for SEEMP Part III Compliance Review
Shipowners and technical managers should review SEEMP Part III before the applicable verification or audit rather than waiting until the final stage of the compliance process.
Early review allows inconsistencies between the documented plan, actual onboard procedures, CII calculations, operational data, and corrective measures to be identified and addressed.
Recommended Preparation
- Confirm that the current SEEMP Part III is available
- Confirm that the document reflects the current vessel particulars
- Review the applicable CII methodology
- Check required and attained annual CII information
- Review the vessel's previous CII ratings
- Review fuel-consumption and operational data
- Verify supporting data-management procedures
- Review the three-year implementation plan
- Identify completed and outstanding efficiency measures
- Review corrective actions where applicable
- Confirm document revision and update history
- Prepare supporting records for verification or audit
11. Technical Review of CII Performance
A technical review of CII performance can help identify the operational factors contributing to a vessel's carbon-intensity rating.
The review should consider the relationship between fuel consumption, propulsion performance, vessel speed, voyage profile, hull and propeller condition, machinery efficiency, operational practices, and other factors relevant to the vessel's CII performance.
Propulsion Performance
Review propulsion efficiency, engine performance, power demand, and operational characteristics affecting fuel consumption.
Hull Condition
Hull fouling, coating condition, and underwater condition can influence resistance and therefore operational energy requirements.
Voyage Efficiency
Voyage planning, speed management, routing, waiting time, and operational patterns can influence the vessel's annual carbon-intensity performance.
Machinery Efficiency
Main and auxiliary machinery condition and operating practices should be considered when assessing opportunities for efficiency improvement.
12. SEEMP Part III as an Ongoing Compliance Management Tool
SEEMP Part III should be integrated into the company's operational carbon-intensity management process. It should not be treated as an isolated regulatory document prepared only for an audit.
Effective management requires the company to compare actual performance with the applicable CII requirements, identify operational trends, evaluate improvement measures, and maintain appropriate records demonstrating how the vessel's carbon intensity is being managed.
This approach also helps technical managers connect environmental compliance with practical vessel-management decisions involving machinery performance, maintenance, voyage planning, fuel consumption, hull condition, and operational efficiency.
13. IMO SEEMP Framework & Current Regulatory Development
The IMO continues to review the short-term greenhouse-gas reduction measures covering EEXI, SEEMP and CII. The review is being conducted in phases and may lead to further development of the carbon-intensity framework.
In 2026, the IMO adopted further amendments to the 2024 SEEMP Guidelines. These developments should be monitored by shipowners and technical managers because the regulatory framework for operational carbon intensity continues to evolve.
Companies should therefore ensure that SEEMP Part III documents are reviewed against the latest applicable IMO requirements, Administration instructions, and recognized-organization procedures rather than relying indefinitely on older templates.
Current SEEMP Framework
The 2024 SEEMP Guidelines provide the current consolidated framework for development of the Ship Energy Efficiency Management Plan.
2026 Amendments
IMO adopted further amendments to the 2024 SEEMP Guidelines at MEPC 84, reflecting the continuing review of the short-term GHG reduction measures.
CII Development
The IMO is continuing work on the future development of CII metrics and the broader carbon-intensity framework.
Regulatory Monitoring
Shipowners and technical managers should monitor new IMO amendments, circulars, guidelines, and applicable Administration requirements.
Independent Marine Surveying & Technical Consultancy
PAMS Pacific Admiralty Maritime Services provides independent marine surveying and technical consultancy support for shipowners, operators, technical managers, offshore projects, and other maritime stakeholders.
Technical services may include marine surveys, technical inspections, condition assessments, regulatory compliance assessments, offshore engineering consultancy, FPSO engineering support, marine audits, and survey preparation.
PAMS can support clients with compliance-focused technical assessments relating to vessel condition, environmental requirements, operational efficiency, technical documentation, regulatory readiness, and preparation for applicable survey and verification activities.
Frequently Asked Questions
What is SEEMP Part III?
SEEMP Part III is the ship operational carbon intensity plan. It provides the vessel-specific framework for calculating and managing operational CII performance, including the applicable methodology, data arrangements, implementation measures, and corrective actions where required.
What is the relationship between SEEMP Part III and CII?
SEEMP Part III provides the management framework for the vessel's operational carbon intensity, while CII provides the applicable operational carbon-intensity measure and annual rating. The vessel's CII performance is therefore an important component of SEEMP Part III management.
Which IMO regulation covers SEEMP Part III?
SEEMP requirements are contained in MARPOL Annex VI Regulation 26. The applicable IMO guidelines provide the detailed framework for development and management of the Ship Energy Efficiency Management Plan.
What does SEEMP Part III contain?
SEEMP Part III can include the review and update log, required annual operational CII, attained annual operational CII and ratings, calculation methodology, required data and data sources, data-quality arrangements, a three-year implementation plan, and applicable corrective actions.
How often should SEEMP Part III be reviewed?
SEEMP Part III should be maintained as a controlled operational document and updated where required by the applicable IMO framework, including where voluntary modifications or necessary corrective actions are involved. Companies should also review the plan against changes to the vessel's operations and the latest applicable regulatory requirements.
What happens if a ship receives a poor CII rating?
Where the applicable IMO requirements trigger corrective action, the company must develop and implement appropriate measures through the SEEMP framework. In particular, a ship rated D for three consecutive years or E is subject to the applicable corrective-action requirements.
What data are important for SEEMP Part III and CII?
Relevant information can include fuel consumption, distance travelled, transport-work data where applicable, vessel operational information, CII calculation parameters, and supporting records required by the applicable IMO requirements and methodology.
Is SEEMP Part III subject to verification?
Yes. IMO has established guidelines concerning verification and company audits by the Administration of Part III of the SEEMP. The applicable verification and certification arrangements depend on the ship, Administration, recognized organization, and relevant statutory requirements.
Can technical measures improve a vessel's CII performance?
Technical and operational measures can contribute to improved CII performance. Depending on the vessel, these may include propulsion-efficiency improvements, machinery optimization, hull and propeller condition management, speed optimization, voyage planning, and other suitable energy-efficiency measures.
Can PAMS support SEEMP Part III and CII compliance preparation?
PAMS Pacific Admiralty Maritime Services provides independent marine surveying and technical consultancy support, including compliance-focused technical assessments, documentation review, vessel condition assessments, marine audits, technical inspections, and preparation for applicable regulatory and verification activities.
PAMS Pacific Admiralty Maritime Services
PAMS Pacific Admiralty Maritime Services is an independent marine technical consultancy specializing in marine surveying, marine technical consultancy, offshore engineering consultancy, FPSO engineering support, marine audits, technical inspections, and maritime compliance services.
Technical consultancy activities include vessel condition assessments, regulatory compliance assessments, marine audits, technical inspections, offshore engineering support, and preparation for applicable statutory and class survey requirements.
Based in Manila, Philippines — operating as an independent technical consultancy serving Philippine and international maritime clients.
Need SEEMP Part III or CII Compliance Support?
PAMS Pacific Admiralty Maritime Services provides independent marine surveying and technical consultancy support for shipowners, operators, technical managers, and maritime projects requiring environmental, energy-efficiency, and regulatory compliance assessments.