CII is the operational Carbon Intensity Indicator expressed in grams of CO2 per deadweight-nautical mile. It is a measure of vessel efficiency of CO2 emitted in transporting cargo or passengers. The CII and CII rating scheme will apply to all Cargo and Cruise ships of 5â000 gross tonnage and above, that is, the ships which are already subject to the requirements of the IMO Data Collection System (IMO DCS).
The annual operational CII achieved or attained CII will be required to be documented and verified against the required annual operational CII. This will enable the Flag state to determine the operational CII rating, the rating will be given on a scale from A to E, A being the better performing vessels.