EEXI & CII Verification Surveys and IMO Energy Efficiency Compliance
The International Maritime Organization has established mandatory energy-efficiency and carbon-intensity requirements for ships through the Energy Efficiency Existing Ship Index (EEXI) and the Carbon Intensity Indicator (CII) framework.
These requirements form part of the IMO strategy to reduce greenhouse gas emissions from international shipping and improve the energy efficiency and operational carbon performance of the global fleet.
EEXI primarily addresses the technical energy efficiency of existing ships, while CII addresses the operational carbon intensity of applicable ships. The two requirements are therefore related but perform different regulatory functions.
Shipowners, operators, technical managers, and responsible personnel should maintain appropriate technical documentation, operational records, calculations, corrective-action records, and verification evidence to demonstrate continuing compliance with the applicable requirements.
IMO Regulatory Framework for EEXI & CII
EEXI and CII requirements were introduced through amendments to MARPOL Annex VI as part of the IMO framework for reducing greenhouse gas emissions from ships.
The regulatory framework applies to ships within the scope of the relevant MARPOL Annex VI requirements and requires shipowners and operators to address both technical energy efficiency and operational carbon intensity.
EEXI
The Energy Efficiency Existing Ship Index is a technical measure addressing the energy efficiency of existing ships based on the applicable ship characteristics, specifications, and technical parameters.
CII
The Carbon Intensity Indicator measures the operational carbon intensity of applicable ships using the relevant annual operational data and applicable IMO calculation methodology.
MARPOL Annex VI
EEXI and CII requirements form part of the greenhouse gas and air-pollution regulatory framework contained within MARPOL Annex VI.
Verification
Applicable EEXI technical documentation and annual CII reporting are subject to verification and certification arrangements through the Administration or authorized recognized organizations, as applicable.
Energy Efficiency Existing Ship Index (EEXI)
The Energy Efficiency Existing Ship Index (EEXI) is a technical energy-efficiency requirement for existing ships within the applicable MARPOL Annex VI scope.
EEXI evaluates the technical energy efficiency of a ship based on its characteristics and approved technical parameters. The calculation is compared with the applicable required EEXI value established under the IMO regulatory framework.
Where a ship requires technical modifications to achieve the applicable EEXI requirement, the technical solution must be properly documented and incorporated into the ship's approved technical documentation.
EEXI Technical Verification Areas
- Main engine power and applicable limitation arrangements
- Ship particulars and principal dimensions
- Installed propulsion machinery
- Reference speed and applicable performance parameters
- Deadweight or applicable capacity parameters
- Propulsion and auxiliary machinery information
- Energy-efficiency technologies incorporated into the vessel
- Approved EEXI technical file
- Required EEXI value and attained EEXI calculation
- Engine power limitation documentation, where applicable
EEXI Technical File & Verification
The EEXI technical file provides the technical basis for the attained EEXI calculation and documents the methodology, assumptions, ship parameters, and technical arrangements used for demonstrating compliance.
The applicable technical documentation should be consistent with the actual ship configuration and with the information contained in the vessel's approved plans, certificates, machinery records, and other technical documentation.
Where an Engine Power Limitation (EPL) or Shaft Power Limitation (SHaPoLi) arrangement is used to achieve the required EEXI, the relevant technical and operational documentation should be maintained and available for verification.
Ship Data
Verification should consider the ship particulars, machinery data, capacity, dimensions, propulsion configuration, and other parameters used in the EEXI calculation.
Calculation Methodology
The attained EEXI calculation should be prepared using the applicable IMO methodology and supported by appropriate technical evidence.
Power Limitation
Where power limitation is used, the applicable technical arrangements, documentation, procedures, and associated safeguards should be properly controlled.
Approval & Verification
The applicable EEXI technical file and associated arrangements are subject to the required approval and verification process under the Administration or delegated organization.
Carbon Intensity Indicator (CII)
The Carbon Intensity Indicator (CII) addresses the operational carbon intensity of applicable ships and forms part of the IMO's operational measures for reducing greenhouse gas emissions from international shipping.
Unlike EEXI, which is primarily a technical design and efficiency requirement, CII is based on the ship's operational performance over the applicable reporting period.
The annual operational carbon intensity is calculated using the applicable IMO methodology and is compared with the required operational carbon-intensity level for the ship.
CII Verification Areas
- Annual fuel consumption data
- Applicable fuel and emissions data
- Distance travelled
- Cargo or capacity information where applicable to the selected CII metric
- Operational data supporting the annual calculation
- Attained annual operational CII
- Required annual operational CII
- Applicable CII rating
- Corrective measures where required
- Records supporting the vessel's annual CII documentation
CII Rating & Corrective Action
Applicable ships receive an annual operational carbon-intensity rating based on their attained CII in relation to the required CII and the applicable rating boundaries.
The rating provides an indication of the vessel's operational carbon-intensity performance and forms part of the IMO framework for improving the efficiency of the existing fleet.
Where the applicable rating indicates that corrective action is required, the ship's technical and operational management should evaluate the underlying causes and implement the required improvement measures in accordance with the applicable regulatory requirements.
Annual Performance
The ship's annual operational data is used to establish the attained CII for the relevant reporting period.
Rating Assessment
The attained annual CII is assessed against the applicable required CII and rating boundaries.
Performance Review
Poor or deteriorating performance should be investigated to identify technical, operational, or voyage-related factors affecting carbon intensity.
Corrective Measures
Where required by the applicable regulatory framework, corrective measures should be documented and incorporated into the vessel's operational improvement process.
CII Data Collection & Operational Records
Reliable operational data is essential for the calculation and verification of a vessel's annual CII.
Technical managers and operators should therefore maintain appropriate records covering fuel consumption, voyages, distances, operational conditions, and other data required under the applicable IMO calculation methodology.
Data quality is particularly important where a vessel's operational performance is being assessed over several reporting periods or where corrective measures are being introduced.
Operational Data Requiring Attention
- Fuel consumption records
- Bunker delivery documentation
- Engine and machinery operating records
- Voyage records
- Distance travelled
- Cargo and capacity information where applicable
- Port and operational records
- Relevant noon reports and electronic operational records
- Data correction records
- Documentation supporting the annual CII calculation
EEXI and CII: Technical Efficiency vs Operational Performance
EEXI and CII should not be treated as identical requirements. They address different aspects of ship energy efficiency and greenhouse gas performance.
EEXI is primarily concerned with the ship's technical energy efficiency, while CII measures operational carbon intensity based on the vessel's actual annual operation.
EEXI – Technical
EEXI focuses on the technical energy efficiency of an existing ship and is demonstrated through the applicable attained EEXI calculation and approved technical documentation.
CII – Operational
CII focuses on the vessel's operational carbon intensity and is determined from the applicable annual operational data.
Technical Measures
Technical measures such as propulsion optimization, power limitation, energy-efficiency devices, and machinery improvements can influence a vessel's energy performance.
Operational Measures
Voyage planning, speed management, weather routing, machinery operation, maintenance, cargo operations, and other operational factors can influence CII performance.
EEXI & CII Technical Survey Preparation
Preparation for EEXI and CII verification should begin with a structured review of the vessel's technical documentation and operational records.
Owners and technical managers should ensure that the information used for calculations is consistent with the vessel's actual configuration and that supporting evidence is available for verification.
EEXI Documentation
Review the approved EEXI technical file, attained EEXI calculation, required EEXI value, technical assumptions, and supporting documentation.
Machinery Data
Verify relevant main engine, propulsion, auxiliary machinery, power limitation, and energy-efficiency information.
CII Records
Review the operational data used for the annual CII calculation and confirm that the supporting records are complete and consistent.
Corrective Measures
Where applicable, review records of measures implemented to improve operational carbon intensity and address identified performance issues.
EEXI Verification: Common Technical Areas for Review
An EEXI verification should consider the relationship between the vessel's approved technical documentation, the actual machinery configuration, and the information used in the attained EEXI calculation.
Particular attention should be given to changes made after the original preparation or approval of the EEXI technical file.
Technical Review Checklist
- Confirm vessel identification and applicable ship particulars
- Review main engine particulars
- Verify applicable engine power information
- Review propulsion configuration
- Verify reference speed information
- Review deadweight or applicable capacity data
- Check the attained EEXI calculation
- Confirm the required EEXI value
- Review EEXI technical file approval status
- Verify EPL or SHaPoLi arrangements where applicable
- Review relevant technical modifications
- Confirm consistency between approved documentation and onboard arrangements
CII Verification: Common Operational Areas for Review
CII verification requires reliable operational data and an appropriate calculation based on the applicable IMO methodology.
A technical review should therefore examine the quality, consistency, and traceability of the data used to establish the vessel's annual operational carbon intensity.
Fuel Data
Review fuel consumption records and supporting bunker documentation used in the applicable annual calculation.
Voyage Data
Review voyage records and distance information supporting the annual operational calculation.
Vessel Data
Confirm that the ship capacity, identification, and other relevant parameters are consistent with the applicable calculation.
Annual Calculation
Review the attained annual CII and supporting calculation records before submission and verification.
Ship Energy Efficiency Management Plan (SEEMP)
The Ship Energy Efficiency Management Plan (SEEMP) forms an important part of the IMO framework for improving the energy efficiency and operational carbon performance of ships.
For applicable ships, SEEMP-related documentation supports the vessel's approach to operational energy efficiency and carbon intensity management.
Where corrective measures or improvement plans are required, the relevant documentation should be maintained and implemented in accordance with the applicable MARPOL Annex VI requirements.
SEEMP-Related Technical Review
- Review applicable SEEMP documentation
- Confirm consistency with the vessel's operational management arrangements
- Review applicable CII management measures
- Review operational efficiency objectives
- Examine relevant corrective-action records
- Verify that applicable records are properly maintained
Technical Measures That Can Influence Energy Efficiency
Technical condition and machinery performance can have a direct influence on the energy efficiency of a vessel and its operational carbon performance.
Technical managers should therefore consider energy performance as part of normal machinery maintenance, condition monitoring, engineering review, and operational planning.
Main Engine Performance
Engine condition, operating parameters, maintenance condition, and combustion performance can influence fuel consumption and overall vessel efficiency.
Propeller Condition
Propeller condition and propulsion efficiency can influence the power required to achieve the vessel's required operating performance.
Hull Condition
Hull fouling, coating condition, and underwater resistance can increase propulsion requirements and fuel consumption.
Auxiliary Machinery
Efficient operation of generators, pumps, compressors, boilers, and other auxiliary equipment can contribute to improved overall energy performance.
Operational Measures That Can Influence CII Performance
CII performance is affected not only by vessel design but also by how the vessel is operated throughout the reporting period.
Operational decisions should therefore be considered together with technical management when evaluating the vessel's carbon intensity.
- Voyage planning
- Appropriate speed management
- Weather and route optimization
- Machinery operating practices
- Hull and propeller condition management
- Cargo planning and operational efficiency
- Reduction of unnecessary fuel consumption
- Monitoring of annual CII performance
- Evaluation of corrective and improvement measures
EEXI & CII Survey Documentation
Proper documentation is essential when preparing a vessel for technical review, statutory verification, or audit relating to energy-efficiency and carbon-intensity requirements.
The exact documents required will depend on the vessel, applicable regulations, Administration requirements, class arrangements, and the verification scope.
Documentation Typically Requiring Review
- Approved EEXI technical file
- Attained EEXI calculation
- Required EEXI calculation
- EPL or SHaPoLi documentation where applicable
- Main engine technical documentation
- Propulsion machinery documentation
- SEEMP documentation where applicable
- Annual fuel consumption records
- Voyage and distance records
- CII calculation documentation
- Annual CII rating documentation
- Corrective-action and improvement records where applicable
EEXI & CII Compliance Preparation Before Verification
Early preparation can reduce the risk of discrepancies between the vessel's approved documentation, onboard configuration, operational records, and submitted compliance information.
Shipowners and technical managers should conduct an internal technical review before the formal verification process where appropriate.
Review Approved Files
Confirm that the applicable EEXI technical file and related documentation remain consistent with the current vessel configuration.
Check Machinery Changes
Identify modifications to propulsion machinery, power limitation systems, energy-efficiency equipment, or other relevant technical systems.
Review Operational Data
Verify the completeness and consistency of operational records supporting the applicable annual CII calculation.
Identify Discrepancies
Identify calculation, documentation, machinery, or operational discrepancies before the formal verification process.
EEXI & CII Technical Survey Checklist
A structured technical checklist can assist shipowners and technical managers in identifying outstanding items before verification or audit.
- Confirm the vessel falls within the applicable MARPOL Annex VI requirements
- Confirm the approved EEXI technical file is available
- Verify the attained EEXI calculation
- Verify the required EEXI value
- Check applicable engine power limitation arrangements
- Review machinery and propulsion documentation
- Confirm applicable SEEMP documentation
- Review annual fuel consumption records
- Review voyage and distance data
- Verify the annual attained CII
- Confirm the applicable CII rating
- Review corrective measures where required
- Check consistency between technical and operational records
- Maintain supporting verification documentation
Relationship Between EEXI, CII and EU MRV
EEXI and CII should also be distinguished from the EU Monitoring, Reporting and Verification (EU MRV) framework.
EU MRV establishes requirements for monitoring, reporting, and verification of relevant ship emissions and related data for ships falling within its applicable geographical and regulatory scope.
The IMO DCS, CII, EEXI, and EU MRV frameworks have different legal bases, scopes, reporting arrangements, and calculation requirements. A vessel may therefore be subject to more than one data and verification regime.
EEXI
Primarily addresses the technical energy efficiency of applicable existing ships.
CII
Addresses the annual operational carbon intensity of applicable ships.
IMO DCS
Establishes the IMO framework for collection and reporting of relevant fuel oil consumption data from applicable ships.
EU MRV
Establishes a separate European monitoring, reporting, and verification framework for ships within its applicable scope.
Why EEXI & CII Compliance Requires Technical Oversight
Energy-efficiency and carbon-intensity compliance is not limited to the preparation of a calculation. The underlying technical condition of the vessel, machinery performance, operational practices, documentation, and data quality can all affect the vessel's compliance position.
Technical oversight can help identify discrepancies between the vessel's approved technical documentation and actual onboard arrangements, as well as weaknesses in operational data or supporting records.
Technical Condition
Machinery, propulsion systems, hull condition, and energy-efficiency equipment should be maintained in accordance with applicable technical requirements.
Documentation
Technical files, calculations, certificates, plans, records, and supporting documents should remain consistent and traceable.
Operational Data
Reliable operational records are essential for accurate annual carbon-intensity calculations and verification.
Continuous Improvement
CII performance should be monitored over time so that deteriorating performance can be identified and addressed through appropriate measures.
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, vessel condition assessments, regulatory compliance verification, marine audits, offshore engineering consultancy, FPSO/SPM technical support, and survey preparation.
PAMS supports clients with compliance-focused technical assessments involving applicable statutory and class requirements, vessel condition, technical documentation, machinery and equipment inspections, offshore operations, and regulatory preparation.
Frequently Asked Questions
What is EEXI?
EEXI stands for Energy Efficiency Existing Ship Index. It is an IMO technical energy-efficiency requirement under MARPOL Annex VI applicable to ships within the relevant regulatory scope.
What is CII?
CII stands for Carbon Intensity Indicator. It is an IMO operational carbon-intensity measure for applicable ships, based on the vessel's annual operational data and the applicable IMO calculation methodology.
What is the difference between EEXI and CII?
EEXI primarily addresses the technical energy efficiency of an existing ship, while CII addresses the vessel's operational carbon intensity based on annual operational performance.
Does EEXI require a technical file?
Yes. Applicable ships require an EEXI technical file supporting the attained EEXI calculation and the technical arrangements used to demonstrate compliance with the applicable MARPOL Annex VI requirements.
What is an EEXI verification survey?
EEXI verification involves review and verification of the applicable technical documentation, calculations, ship particulars, and technical arrangements used to demonstrate compliance with the applicable EEXI requirements.
Is CII assessed annually?
Yes. The attained annual operational CII is calculated for the relevant reporting period and is assessed against the applicable required CII and rating boundaries.
What information is needed for a CII calculation?
The applicable CII calculation requires relevant operational data, including fuel consumption and other ship and voyage information required by the applicable IMO calculation methodology.
What happens if a vessel has poor CII performance?
Where the applicable CII rating and regulatory requirements require corrective action, the ship's technical and operational management should evaluate the vessel's performance and implement the applicable improvement and corrective measures.
Is EEXI the same as IMO DCS?
No. EEXI is primarily a technical energy-efficiency requirement, whereas the IMO Data Collection System (DCS) establishes requirements for collecting and reporting relevant fuel oil consumption data from applicable ships.
Is EU MRV the same as CII?
No. EU MRV and IMO CII are separate regulatory frameworks with different legal bases, scopes, reporting requirements, and methodologies. A vessel may be subject to more than one framework depending on its operations and applicable regulations.
Can technical condition affect CII performance?
Yes. Factors such as hull condition, propeller condition, machinery performance, propulsion efficiency, and auxiliary machinery operation can influence fuel consumption and therefore affect operational carbon-intensity performance.
Can PAMS provide independent EEXI and CII technical support?
PAMS Pacific Admiralty Maritime Services provides independent marine surveying, technical inspection, condition assessment, regulatory compliance verification, marine audit, and technical consultancy support for shipowners, operators, technical managers, and offshore projects.
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 regulatory compliance.
Technical compliance services include statutory and class survey preparation, vessel condition assessments, technical equipment inspections, regulatory compliance verification, offshore engineering support, and audit preparation.
Based in Manila, Philippines — operating as an independent technical consultancy.
Need EEXI, CII or Energy Efficiency Compliance Support?
PAMS Pacific Admiralty Maritime Services provides independent marine surveying and technical consultancy support for shipowners, operators, technical managers, and offshore projects.