North Pole Since 2002, the Russians have also annually established a base, Barneo, close to the Pole. This operates for a few weeks during early spring. Studies in the 2000s predicted that the North Pole may become seasonally ice-free because of Arctic ice shrinkage, with timescales varying from 2016 to the late 21st century or later. The sea depth at the North Pole has been measured at by the Russian Mir submersible in 2007 and at 4,087 m (13,410 ft) by USS "Nautilus" in 1958. The nearest land is usually said to be Kaffeklubben Island, off the northern coast of Greenland about
Skate-class submarine Skate-class submarine The "Skate"-class submarines were the United States Navy's first production run of nuclear-powered submarines. They were an evolution of the in everything except their propulsion plants, which were based on the operational prototype . The four "Skate" class boats re-introduced stern torpedo tubes. Although among the smallest nuclear-powered attack submarines ever built, the "Skate" class served for many years, with the last being decommissioned in 1989. USS "Skate" was the first submarine to surface at the North Pole, on 17 March 1959. "Skate" and "Sargo" were built with the S3W reactor, "Swordfish" and "Seadragon" also had the S3W