Navy shipboard fuels are subjected to an environment, combat reliability requirements, and occasionally long-term storage that impose stability and cleanliness needs not normally required for fuels for shore use. The Navy satisfies those needs through specifications imposing more constraints than similar American Society for Testing and Materials (ASTM) specifications, through a strict inspection system, and through quality testing at various steps in the acquisition and distribution system. This Navy quality-control system is described. Statistical data based upon inspection data from a random sampling of fuel acquired between February 1977 and January 1980 are presented. Results of an extensive survey of fuel received and used by one class of ships which bunkered at ports around the world are given. Data include the amount, nature, and size of particulate matter, as well as the contents of water, sodium, and copper.