Compliance watch: CII ratings and MARPOL Annex VI

A vessel compliant today can drift into a lower CII band without any change on board. A reminder of the A–E rating regime and where retrofit fits in.

Since 1 January 2023, ships of 5,000 GT and above trading internationally are rated annually from A to E for operational carbon intensity (CII) under MARPOL Annex VI, alongside the technical EEXI. A ship rated D for three consecutive years, or E for one year, must submit a corrective action plan in its SEEMP.

The required annual CII reduction tightens each year, so a vessel that is compliant today can drift into a lower band without any operational or technical change. Levers include speed and voyage optimization, hull and propeller cleaning, and technical retrofit — engine tuning, energy-saving devices and alternative fuels.

Heads-up: further MARPOL amendments affecting fuel-consumption reporting and engine emission tiers are advancing through the IMO. Verify the latest applicable requirements with your flag administration or Recognized Organization before fixing a retrofit scope.

You can use the free CII / FuelEU calculator on this site to estimate your rating trajectory and potential EU charges before committing to any work.