In 1966, Marley married Rita Anderson, and moved near his mother's residence in Wilmington, Delaware in the United States for a short time, during which he worked as a DuPont lab assistant and on the assembly line at a Chrysler plant in nearby Newark, under the alias Donald Marley.
USS Queenfish was the first nuclear-powered warship to visit Australia. Queenfish berthed at Station Pier, Melbourne, on 5 March 1968. The visit was a success, despite anti-nuclear protests. Queenfish spent the early months of 1967 practicing under-ice operations in the Davis Strait.