Severnaya Zemlya any traces of land to the north of the wide strait between the Kara Sea and the Laptev Sea that they navigated. The archipelago was not put on the map until the 1913–1915 Arctic Ocean Hydrographic Expedition of icebreakers "Taimyr" and "Vaigach". The chief organiser and first captain of the Vaygach was officer Aleksandr Vasiliyevich Kolchak of the Imperial Russian Navy. The expedition was privately financed and was launched in 1910, being led by Boris Vilkitsky on behalf of the Russian Hydrographic Service. This venture accomplished its goal of exploring the uncharted areas of the continental side of the Northern
Novaya Zemlya numbering 298, was removed to the mainland in 1957 before nuclear testing began. In 1943, during World War II, Novaya Zemlya briefly served as a secret seaplane base for Nazi Germany's "Kriegsmarine", to provide German surveillance of Allied shipping en route to Siberia. The seaplane base was established by U-255 and U-711, which were operating along the Northern coast of Soviet Russia as part of "13th U-boat Flotilla". Seaplane sorties were flown in August and September 1943. In the months following Hitler’s June 1941 invasion of the Soviet Union, the United States and Great Britain organized convoys of merchant ships