Question: For which feat of endurance is the Norwegian explorer, photographer, writer and former deep sea diver for the oil industry whose diving was mostly carried out in a marginal sea of the Atlantic Ocean located between Great Britain and Scandinavia and whose name is Børge Ousland, best known?

<P0-S0> The North Sea is a marginal sea of the Atlantic Ocean located between Great Britain, Scandinavia, Germany, the Netherlands, Belgium, and France. <P0-S1>  An epeiric (or "shelf") sea on the European continental shelf, it connects to the ocean through the English Channel in the south and the Norwegian Sea in the north. <P0-S2>  It is more than 970 km long and 580 km wide, with an area of around 570000 km2 . <SEP> <P1-S0> The Greenland Sea is a body of water that borders Greenland to the west, the Svalbard archipelago to the east, Fram Strait and the Arctic Ocean to the north, and the Norwegian Sea and Iceland to the south. <P1-S1>  The Greenland Sea is often defined as part of the Arctic Ocean, sometimes as part of the Atlantic Ocean. <P1-S2>  However, definitions of the Arctic Ocean and its seas tend to be imprecise or arbitrary. <P1-S3>  In general usage the term "Arctic Ocean" would exclude the Greenland Sea. <P1-S4>  In oceanographic studies the Greenland Sea is considered part of the Nordic Seas, along with the Norwegian Sea. <P1-S5>  The Nordic Seas are the main connection between the Arctic and Atlantic oceans and, as such, could be of great significance in a possible shutdown of thermohaline circulation. <P1-S6>  In oceanography the Arctic Ocean and Nordic Seas are often referred to collectively as the "Arctic Mediterranean Sea", a marginal sea of the Atlantic. <SEP> <P2-S0> Mike deGruy (December 29, 1951 – February 4, 2012) was an American documentary filmmaker specialising in underwater cinematography. <P2-S1>  His credits include "Life in the Freezer", "Trials of Life", "The Blue Planet" and "Pacific Abyss". <P2-S2>  He was also known for his storytelling, most notably, a passionate TED talk about his love of the ocean on the Mission Blue Voyage. <P2-S3>  His company, Film Crew Inc., specialized in underwater cinematography, filming for BBC, PBS, National Geographic, and The Discovery Channel. <P2-S4>  His notable accomplishments include diving beneath thermal vents in both the Atlantic Ocean and Pacific Ocean. <P2-S5>  He was a member of many deep sea expeditions and was a part of the team that first filmed the vampire squid and the nautilus. <P2-S6>  He was also part of the Deepsea Challenge, where James Cameron went to the bottom of the Mariana Trench. <P2-S7>  In 2016, production began on a feature-film documentary about his life and work titled Diving Deep. <P2-S8>  The documentary is planned for release in 2017. <P2-S9>  Additionally, Mike was well-known for his shark attack on April 2, 1978 by a grey reef shark, and was severely bitten on his lower right forearm, from which he bore scars. <SEP> <P3-S0>  He started his career as a Norwegian Navy Special Forces Officer with Marinejegerkommandoen, and he also spent several years working as a deep sea diver for the oil industry in the North Sea. <P3-S1>  In 1994, he made the first solo and unsupported journey to the North Pole from cape Arktichevsky in Russia. <P3-S2> Børge Ousland (born 31 May 1965) is a Norwegian polar explorer, photographer and writer. <P3-S3>  As of 2016, that feat has never been successfully repeated. <P3-S4>  He made the first unassisted Antarctic solo crossing, between 15 November 1996 and 17 January 1997. <P3-S5>  The ski journey was made with kite assistance and also holds the record for the fastest unsupported journey to the South Pole taking just 34 days. <P3-S6>  On 22 January 2006, together with Mike Horn he began a journey to the North Pole in full Arctic night, successfully concluded on 23 March.