The largest ocean current on Earth is the Antarctic Circumpolar Current (or West Wind Drift). It goes around the whole planet and connects the three oceans: the Atlantic, Indian and Pacific.

The second name of the current comes from the westerly winds, which drive it. ACC gives sailors a lot of problems: it creates quite a rough environment to sail in. A lot of well-known sailors described the ACC and the troubles it caused in their journals. For example, James Cook and James Clark Ross were amused by its power, and the British astronomer Edmund Halley was the first one to discover the current in his 1699-1700 expedition.

More Info: polardiscovery.whoi.edu