Explorers do the strangest things.
In 1930, encouraged by William Randolph Hearst, the Prince of Wales and Jules Verne's grandson, an Australian kangaroo hunter embarked in a World War I surplus submarine on a voyage beneath the ice to the North Pole, taking along a gravimeter, oceanographic sampling gear and a weather station.
He stopped 600 miles short, but came back with the first measurements of the oblateness of the Earth, having discovered the Atlantic Meridonal Overturning Circulation along the way:
