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
French submarine Espadon (S637) front of her sail. On 13 August 1963 a fire in the torpedo room wounded and intoxicated four sailors, one of whom later died of his wounds. In May 1964, "Espadon" and "Marsouin" steamed under sea ice in the Norwegian Sea as far as 70° north. "Espadon" undertook significant modifications from 1966 to 1968, notably upgrading the boat's sonar, sail and rudders. "Espadon" has been a museum ship at the "ville-port" of Saint-Nazaire in the German-built submarine base since 1987. French submarine Espadon (S637) Espadon was a "Narval"-class submarine of the French Navy. Along with sister boat "Marsouin", the boat