History of submarines few years before the US, and paralleled subsequent US development in this area. In the 1950s, nuclear power partially replaced diesel-electric propulsion. The sailing of the first nuclear-powered submarine, the USN ""Nautilus"" in 1955 was soon followed by similar British, French and Russian boats. Equipment was also developed to extract oxygen from sea water. These two innovations, together with inertial navigation systems, gave submarines the ability to remain submerged for weeks or months, and enabled previously impossible voyages such as the crossing of the North Pole beneath the Arctic ice cap by the USS "Nautilus" in 1958. Most of the
North Pole Marathon North Pole Marathon The North Pole Marathon is run over the classic 42.195 km (26.2 miles) marathon distance at the North Pole. The race is run on small, 4.22 km (2.62-mile) loop about 10 times over hard snow or the frozen ice of the Arctic Ocean. There are individual competitions with male and female divisions, and a team competition for teams of three or more. There is also an option to run a half marathon. The North Pole Marathon has been recognized by Guinness World Records as the "Northernmost Marathon on Earth". The first unofficial North Pole Marathon was a