The merchant shipping industry has failed a second time to short-circuit California's effort to combat the toll on the health of its population from air pollution caused by oceangoing vessels. The industry is contesting California's authority to regulate fuel used by seagoing vessels up to 24 miles off its coast. The Air Resources Board estimates the vessels' emissions of particulate matter cause 300 premature deaths across the state every year. California mandates that ships "use cleaner marine fuels in diesel and diesel-electric engines, main propulsion engines, and auxiliary boilers" while operating far beyond the traditional three-mile jurisdictional limit. The Pacific...