The USS Interdictor was a radar picket ship belonging to the Guardian-class that was acquired by the US Navy in 1957 from the reserve fleet to be used as a radar picket ship as part of the Distant Early Warning Line in the Pacific Ocean. The ship was launched as Liberty Ship SS Edwin H. Duff by J.A. Jones Construction Company in Panama City, Florida. During World War II, the ship carried aircraft and then it was placed in the reserve fleet at James River, Virginia where it remained until it was acquired by the Navy in 1957. After its conversion, the ship was fitted with radar and tracking equipment and sailed for San Francisco, California where it carried out its radar picket duties for the US Navy and later, for the Continental Air Defense Command until it was decommissioned in August 1965. The ship was transferred to the US Maritime Administration and laid up in the reserve fleet at Suisun Bay, California. It was sold in June 1974.