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
Lake North Pole Lake North Pole Lake North Pole, also known as The North Pool, is a small, shallow lake near the North Pole, and is currently the northernmost lake in the world. It came into existence in 2002, occurring each year, then freezing over in the winter. The lake, which is approximately one foot deep, is composed almost entirely of fresh water melted from the ice beneath. A web camera is stationed beside the lake to monitor changes. It was built by the Polar Science Center. On July 26, 2013, the depth was estimated to be approximately 40 cm. Members of the