Each of the major ocean basins is unique, but the South Atlantic is unrivaled in its number of singular features. In its polar region are formed intermediate and bottom water masses that cool and lower the salinity of much of the global ocean. The subtropical region has an eastern boundary that doesn’t quite extend to the latitude of maximum westerlies, allowing thermocline communication with its counterpart in the South Indian Ocean. Within the Argentine Basin of the South Atlantic one can sample deep water from the North Atlantic, deep and intermediate water from the Pacific, and bottom water formed in the Weddell Sea. These water masses spread and vigorously mix within tiffs cosmopolitan basin and throughout much of the South Atlantic.