The Cruise Lines International Association (CLIA) reported significant progress in environmental technologies among its member cruise lines. According to the data, 30 passenger ships now use dual-fuel engines, up from just one in 2018. These systems are designed to switch to near-zero-emission fuels once they become widely available at scale.
The association’s order book projects 31 dual-fuel ships in service by the end of 2026, with 56 expected by 2030. By 2039, CLIA estimates 69 vessels could be equipped with the technology. Heavy fuel oil (HFO) consumption has declined from 74.2% of total fuel use in 2019 to 60.6% in 2024, while non-HFO fuels increased from 25.8% to 39.4%. CLIA forecasts its members will reach 40.3% non-HFO usage by 2025.
Shore power connections (OPS) represent another focus area. The number of CLIA member ships capable of connecting to shore power rose from 55 in 2018 to 193 in 2026, representing 65% of reporting vessels and 72.5% of declared capacity. However, only 40 global ports currently offer at least one OPS-equipped cruise terminal. To meet demand, 47 existing ships need retrofitting, and 39 new builds will incorporate OPS from the start. CLIA projects approximately 279 ships could have OPS capability by 2039.
Onboard water production has become widespread, with 293 ships (98.7% of reporting vessels) able to generate freshwater. Among them, 218 can theoretically meet 100% of their needs. Wastewater treatment has also advanced, with all CLIA member vessels currently in service equipped with treatment systems. Advanced Wastewater Treatment Systems (AWTS) increased from 136 in 2018 to 249, enhancing environmental compliance.
By August 2026, 45 CLIA member cruise lines will operate 327 ships, carrying roughly 692,000 berths—over 90% of global ocean cruise capacity. Most vessels remain small or medium-sized, with 72% under 3,000 berths. This proportion is expected to stabilize through 2039, though large ships will grow from 28.3% to 31.8% of the fleet. The trend contrasts with broader maritime shifts toward larger, more efficient vessels for cost and capacity reasons.
Waste management technologies have expanded alongside fuel and water systems. Microbial digesters for food waste rose to 137 ships in 2023 from 103 in 2022. These systems reduce landfill reliance and support CLIA’s 2050 carbon neutrality goal. Progress in dual-fuel adoption and shore power access highlights the industry’s commitment to cleaner operations, though infrastructure gaps, especially in port facilities, remain a limiting factor for full implementation.