Challenger sailed from the United Kingdom on 21 December 1872. The account gives priority to the officers' contemporary figure of roughly 68,000 miles, while acknowledging later historians who argue that accumulated navigational error may have made the actual distance longer. The voyage lasted five years, enough time for small measurement errors to compound across a global track. Its surface-water density observations offered clues to temperature, currents, composition, and the physical behavior of oceans covering most of the planet.
Notable Point · 7:44-10:18
A global voyage and the meaning of ocean density
Challenger's roughly 68,000-mile voyage gathered measurements that connected surface-water density to temperature, currents, and ocean composition.