CII (Carbon Intensity Indicator)
The annual A-E rating that in 2026 requires an 11% reduction versus 2019 — and that, unlike EEXI, must be recalculated every year against increasingly strict thresholds.
Operational Explanation
The Carbon Intensity Indicator (CII) measures a ship's actual operational efficiency (not just its design efficiency), expressed as an annual A-E rating, calculated after the fact based on actual fuel consumption and distance travelled in the reference year. Unlike EEXI, CII must be recalculated every year, with required reduction factors (relative to the 2019 baseline) increasing progressively: from 5% required in 2023 to 11% in 2026, rising to 21.5% by 2030.
A ship that receives a 'D' rating for three consecutive years, or an 'E' rating even in a single year, must develop a Corrective Action Plan documenting how it intends to reach at least a 'C' rating, to be formally included in SEEMP Part III and submitted for approval.
Regulatory Reference
MARPOL Annex VI, Chapter 4 (Regulation 28): annual CII calculation with an A-E rating; requirement for a Corrective Action Plan for a D rating (3 consecutive years) or E rating (even a single year), to be included in SEEMP Part III.
Scope of Application
Cargo and passenger ships of 5,000 gross tonnage and upwards, subject to annual CII reporting to the Flag Administration.
Procedure / How to Complete It
- Systematically collect fuel consumption and distance-travelled data during the year, per IMO DCS requirements.
- Calculate the annual CII after the fact and determine the rating (A-E) against the threshold required for the reference year.
- If the rating is D for the third consecutive year, or E even for a single year, develop a detailed Corrective Action Plan.
- Include the Corrective Action Plan in SEEMP Part III, submitting it for formal approval per the required procedure.
- Monitor implementation of the corrective measures during the following year, verifying their effect on the rating.
Diagram: when the Corrective Action Plan (CII) is triggered
Practical Example
Management example: a ship with a D rating for the third consecutive year in 2026; a Corrective Action Plan is developed combining cruising speed optimization, route revision to reduce ballast miles, and targeted hull maintenance (hull cleaning) to reduce hydrodynamic resistance, targeting a C rating by the following year.
Real Cases
Common Mistakes Mistake Library
| Mistake | Consequence | How to avoid it |
|---|---|---|
| CII rating monitored only at year-end, without intra-year projections | Late discovery of an insufficient rating, with no time for corrective action within the current year | Monitor intra-year CII projections, do not wait for the year-end calculation |
| Generic Corrective Action Plan, without specific and measurable measures | Ineffective plan, rating that does not improve the following year | Develop a plan with specific, measurable measures and assigned responsibilities |
| Consumption/distance data not collected with sufficient precision for a reliable calculation | Rating calculated imprecisely, with risk of incorrect reporting | Ensure the quality and consistency of data collection throughout the year, not only after the fact |
PSC Observations
Operational Tips
- Monitor intra-year CII projections to act before year-end, not after.
- Develop Corrective Action Plans with specific, measurable measures, not generic statements of intent.
- Do not rely solely on passive measures (like EPL): combine operational actions (speed, routes) and technical ones (hull maintenance) for lasting improvement.
Checklist
- Consumption and distance data systematically collected per IMO DCS
- CII rating calculated annually and monitored with intra-year projections
- Corrective Action Plan developed for a D rating (3 years) or E rating (1 year)
- Plan included in SEEMP Part III and formally approved
- Implementation of corrective measures monitored over time