During World War II, the SS Coast Trader was hit by a torpedo and sank off the coast of Washington State. A recent dive to evaluate the vessel’s integrity showed potential signs of a leak from its 542 tons of heavy fuel oil aboard. NOAA’s Office of Response & Restoration began a comprehensive assessment of the Coast Trader’s fuel were it to fully leak, modeling potential paths and the impacts on the coastline. Thanks to Coast Survey’s West Coast Operational Forecast System, which provides water level, current, temperature, and salinity nowcast and forecast guidance, the team ran 400 spill scenarios for each season and determined the likely path for cleanup efforts—which changes based on the time of year the spill would occur.