Heavy fuel oil accounted for 60.6% of reported fuel use by oceangoing cruise lines in 2024, down from 74.2% in 2019, according to a statement from Cruise Lines International Association (CLIA).
The 16 September release said the figures were based on fuel volumes submitted by cruise passenger ships to the International Maritime Organization’s Ship Fuel Oil Consumption Database.
Non-HFO fuels, including marine diesel and gas oil, very-low and ultra-low sulphur fuel oil, LNG and other fuel pathways, increased their combined share from 25.8% in 2019 to 39.4% in 2024. CLIA’s own tracking put non-HFO use at 40.3% in 2025.
CLIA linked the shift to more efficient ships, operational improvements, itinerary planning and investment in fuel flexibility rather than a single technology.
The number of CLIA-member ships with multi-fuel engines has risen from one in 2018 to 30, with 56 expected in service by the end of 2030 and 69 by 2039. Shore-power capability has climbed from 55 ships in 2018 to 193, covering 65% of reporting ships and 72.5% of reporting capacity.
Another 47 ships are planned for retrofits and 39 newbuildings are specified with the technology.
CLIA expects 279 ships, or 82% of projected capacity, to have shore-power capability by 2039, while only 40 ports worldwide where cruise ships call currently have at least one equipped berth.
Average fuel consumption per reporting cruise ship sailing in Europe fell about 18.5% between 2018 and 2025, while average CO2 emissions per ship declined about 19.4%.
Selective catalytic reduction systems are fitted on 96 ships, up from seven in 2018. Advanced wastewater treatment systems are installed on 249 ships, or 83.8% of reporting vessels, compared with 136 in 2018. Of these, 124 can meet the more stringent standards for passenger ships in the Baltic Sea Special Area under MARPOL Annex IV.
The figures also list 159 ships with exhaust gas cleaning systems, but do not establish those systems as the cause of the decline in HFO’s share.
“Year after year, the data show cruise lines continuing to invest in the technologies, fuels, and operational capabilities,” CLIA president and chief executive Bud Darr said.
CLIA is a Washington, DC-based global cruise industry trade association. As of August 2026, its 45 oceangoing cruise line members operated 327 ships with about 692,000 lower berths, representing more than 90% of global oceangoing cruise capacity. The 2026 environmental technologies survey covered 297 ships, equal to 96% of member ships and 98% of member capacity.