What this is. Ships of 5,000 GT and above report fuel use, distance and hours under way to their flag each year (MARPOL Annex VI, reg. 27), and IMO publishes an aggregated report. In 2024 that covered 29,690 ships: 82.1% of the ships IMO estimates are in scope by number, 91.0% by gross tonnage.
Reconciled, not retyped. We parsed the ship-type tables in each report and checked that every row adds up to IMO's printed totals, for every year. Two inconsistencies inside IMO's own reports are handled in the open: in 2024 the ship-type rows and the Total row split 171,135 t differently between HFO and “Other” (we use the Total row for All ships), and the 2023 annex total is one ship higher than the report body (we use the body).
CO₂. IMO publishes CO₂ from 2022. For 2019–2021 we compute it as IMO's fuel figures × IMO's carbon factors (HFO 3.114, LNG 2.750 t CO₂ per tonne, and so on), counting “Other” fuels at the HFO factor. Those fuels were under 0.1% of the total in those years, so that choice moves CO₂ by less than 0.1%. Applied to 2022–2024, the same method lands within 0.25% of IMO's published figure.
Totals or per ship. More ships report each year (27,221 in 2019, 29,690 in 2024), so totals rise partly through wider coverage. The “Per ship” view takes that out, though the mix of ships still shifts.
Fuel types are shown as reported. IMO notes that low-sulphur heavy fuel oil may be reported as HFO, and that biofuels sit under “Other” with no standard composition.
CII shares are taken over ships that reported a rating, so 2023 and 2024 compare like for like. IMO's own headline percentages use different bases (all reporting ships in 2023, ships subject to CII in 2024).
Ship-type groups. “Ro-ro & vehicle” is ro-ro cargo ships plus vehicle carriers. “Passenger & cruise” is cruise, ro-ro passenger and other passenger ships. “Reefer & other” is refrigerated cargo carriers, combination carriers and IMO's “Others” (dredgers, pipe-layers and similar). Gas carriers exclude LNG carriers, as in IMO's tables.
The 2030 outlook is arithmetic on the rules, not a forecast: required CII = (1 − Z) × the 2019 reference line, with Z from MEPC.338(76) and MEPC.400(83) and rating bands from MEPC.354(78). It ignores correction factors and voyage adjustments, and offers only the ship types whose bands are verified in our rules engine.
Spotted an error? Tell us at info@navallogic.com. We would rather fix it than defend it.
