 After a one-year sabbatical from the NPS in 1984-1985 to attend East Carolina University, Delgado gained a master's degree in Maritime History and Underwater Research and was subsequently assigned by NPS Chief Historian Edwin C. Bearss to work as project historian on the USS Monitor project with the National Oceanic and Atmospheric Administration(NOAA).That work led to a series of historical and archaeological context studies, and Delgado personally completed the successful nomination for Monitor's designation as one of the first National Historic Landmark shipwrecks in the United States.He subsequently completed the National Historic Landmark studies for the wrecks of USS Arizona and USS Utah at Pearl Harbor.