In an effort to slash harmful emissions from ocean-going vessels, EPA is proposing a Clean Air Act rule that sets tough engine and fuel standards for U.S.-flagged ships. The new rule is intended to harmonize with international standards and lead to significant air quality improvements throughout the country. The rule comes quickly after the March proposal by the United States and Canada to designate thousands of miles of the two countries' coasts as an Emission Control Area (ECA). When fully implemented, the coordinated effort would reduce NOx emissions by 80 percent and PM emissions by 85 percent compared to current emissions. The proposed rulemaking adds two new tiers of NOx standards and strengthens EPA's existing diesel fuel program for these ships.