Maritime Glossary
Carbon Intensity Indicator
Also known as: CII
An IMO operational rating that measures a ship's CO₂ efficiency and assigns an annual grade from A (best) to E.
Status: ActiveVerified: Source confidence: high (96%)
Full Definition
The Carbon Intensity Indicator (CII) is an operational efficiency metric under MARPOL Annex VI (Regulation 28), mandatory from 2023. It measures grams of CO₂ per cargo-carrying capacity and nautical mile, benchmarked against ship-type reference lines. Ships receive annual grades A–E; those rated D for three consecutive years or E for one year must submit a corrective action plan to the flag state. CII applies to ships ≥5,000 GT engaged in international voyages.
Domain Tags
decarbonizationregulation