http://www.epa.gov/oms/regs/nonroad/marine/ci/420f10041.htm
The Proposed U.S. Caribbean ECA
The area of the proposed U.S. Caribbean ECA includes waters adjacent to coasts of the Commonwealth of Puerto Rico and the U.S. Virgin Islands. The northern and southern boundaries of the proposed area would extend roughly 50 nautical miles (nm) and 40 nm, respectively, from the territorial sea baseline of the main island of Puerto Rico. The western edge of the proposed area would generally run north-south, about half way between the Puerto Rican island of Mona and the west coast of the main island. The eastern edge of the proposed area would generally run north-south, but extend eastward through the area between the U.S. Virgin Islands and the British Virgin Islands and also eastward through the area between Saint Croix and Anguilla and Saint Kitts. The proposed ECA is bounded such that it does not extend into marine areas subject to the sovereignty, sovereign rights, or jurisdiction of any state other than the United States.
http://www.epa.gov/oms/oceanvessels.htm
North American Emission Control Area
On March 26, 2010, the IMO officially designated waters off North American coasts as an area in which stringent international emission standards will apply to ships. These standards will dramatically reduce air pollution from ships and deliver substantial air quality and public health benefits that extend hundreds of miles inland.
In 2020, EPA expects emissions from ships operating in the designated area to be reduced by 320,000 tons for NOx, 90,000 tons for PM2.5, and 920,000 tons for SOx, which is 23 percent, 74 percent, and 86 percent, respectively, below predicted levels in 2020 absent the ECA.
In practice, implementation of the ECA means that ships entering the designated area would need to use compliant fuel for the duration of their voyage that is within that area, including time in port as well as voyages whose routes pass through the area without calling on a port. The quality of fuel that complies with the ECA standard will change over time. From the effective date in 2012 until 2015, fuel used by all vessels operating in designated areas cannot exceed 1.0 percent sulfur (10,000 ppm). Beginning in 2015, fuel used by vessels operating in these areas cannot exceed 0.1 percent sulfur (1,000 ppm). Beginning in 2016, NOx afte rtreatment requirements become applicable
http://www.epa.gov/oms/regs/nonroad/marine/ci/420f10015.htm
The area of the North American ECA includes waters adjacent to the Pacific coast, the Atlantic/Gulf coast and the eight main Hawaiian Islands.1 (footnote). It extends up to 200 nautical miles from coasts of the United States, Canada and the French territories, except that it does not extend into marine areas subject to the sovereignty or jurisdiction of other States.