Incredibly dangerous to navigate by ship:
http://www.atlanteanconspiracy.com/2015/06/south-pole-does-not-exist.html
Vasco de Gama, an early 16th century Portuguese explorer of the South Seas wrote how, “The waves rise like mountains in height; ships are heaved up to the clouds, and apparently precipitated by circling whirlpools to the bed of the ocean. The winds are piercing cold, and so boisterous that the pilot’s voice can seldom be heard, whilst a dismal and almost continual darkness adds greatly to the danger.â€
On October 5th, 1839 another explorer, James Clark Ross began a series of Antarctic voyages lasting a total of 4 years and 5 months. Ross and his crew sailed two heavily armored warships thousands of miles, losing many men from hurricanes and icebergs, looking for an entry point beyond the southern glacial wall. Upon first confronting the massive barrier Captain Ross wrote of the wall, “extending from its eastern extreme point as far as the eye could discern to the eastward. It presented an extraordinary appearance, gradually increasing in height, as we got nearer to it, and proving at length to be a perpendicular cliff of ice, between one hundred and fifty feet and two hundred feet above the level of the sea, perfectly flat and level at the top, and without any fissures or promontories on its even seaward face. We might with equal chance of success try to sail through the cliffs of Dover, as to penetrate such a mass.â€