New standards that reduce the amount of sulfur in marine fuel may be delayed five years, the International Maritime Organization said in a briefing statement Tuesday.
The delay would hinge on the outcome of a study of the availability of low-sulfur fuels.
The organization's Marine Environmental Protection Committee said that residual fuels currently average a sulfur content of 2.65% by weight, while distillate fuels average 0.14%.
At a recent meeting in London, the committee discussed whether to commission a study of the availability of fuel in advance of deadlines for reducing sulfur to curb air pollution.
Rules now call for sulfur content to fall from 3.5% to 0.5% by 2020. The deadline could be pushed back to 2025 depending on the study results, the panel said.
The rules in question are for operations outside of designated Emission Control Areas, where sulfur content is capped at 1% and must fall to 0.1% by 2015.
One estimate says the new rules could add $15 to $18 a day to the cost of a cruise. Follow Tom Stieghorst on Twitter @tstravelweekly.com.