North Pole Expedition - Russian Ice Camp BARNEO - Philippe LATTES. 

because what you see in the 4200 deep arctic ocean which is covered by permanent drifting ice , everything is floating ice sheets the camp stays for a month period on april at summer ice melts , arctic ocean is deep as any ocean with abyssal plains

This is very close to the North Pole where the sun moves at the same position above the horizon for 6 months.