John Francis Ropek this nuclear submarine, Ropek was involved in pioneering oceanographic studies under the polar ice cap of the North Pole, resulting in the report "Characteristics of Polar Ice Observed During the 1957 Arctic Cruise of the USS Nautilus" (Defense Technical Information Center 1958). As a scientist he published many technical papers, such as "US Navy Hydrographic Office synoptic and prognostic wave charts" (US Navy Hydrographic Office 1955), and "An Application of Naval Oceanographic Development to Inland Waters" (Defense Technical Information Center 1967). Later, Ropek was deputy director of the prediction division of the Naval Oceanographic Office. Late in life he lived
Submarine Soviet Union () as part of the Cold War nuclear deterrent strategy. During the Cold War, the US and the Soviet Union maintained large submarine fleets that engaged in cat-and-mouse games. The Soviet Union lost at least four submarines during this period: was lost in 1968 (a part of which the CIA retrieved from the ocean floor with the Howard Hughes-designed ship "Glomar Explorer"), in 1970, in 1986, and in 1989 (which held a depth record among military submarines—). Many other Soviet subs, such as (the first Soviet nuclear submarine, and the first Soviet sub to reach the North Pole)