What is the CII concept under MARPOL Annex VI chapter 4 and its commercial impact?

flowchart TD
    A["MARPOL Annex VI chapter 4"] --> B["Regulation 26: SEEMP"]
    A --> C["Regulation 27: Data collection"]
    A --> D["Regulation 28: Operational CII"]
    B --> E["Methodology for CII calculation"]
    C --> F["Fuel consumption, distance, hours under way"]
    D --> G["Attained CII vs Required CII"]
    G --> H["Rating A-E"]
    H --> I["Corrective action for Dx3 or E"]
    H --> J["Incentives for A or B"]

• CII is the operational limb of MARPOL Annex VI chapter 4, grading annual efficiency (A-E).
• Required CII = (1 - Z/100) x CII_R, with Z increasing progressively.
• D for 3 years or E triggers a verified corrective action plan in SEEMP within 1 month.
• Commercial impact: comparable, verified grades influence chartering, financing, and asset value.
• Trap: Rating driven by commercial decisions (speed, routing), not just engineering.
• Review by 1 JANUARY 2026 to address shortcomings (e.g., distance vs cargo, uncontrollable time).