The IMO’s Carbon Intensity Indicator (CII) rating system for vessels is coming into force next year. It will be used to assess the efficiency with which a ship operates. It is the first carbon regulation from the IMO that is likely to alter the traditional division of responsibilities between owners and time charterers and may significantly change the way vessels are operated. For those less familiar with the CII regulations, see our accompanying article "[The challenges of CII compliance - cooperation is key](https://gard.no/insights/the-challenges-of-cii-compliance-cooperation-is-key/)".