The earth's five oceans are the Indian, Arctic, Southern Antarctic, Atlantic and Pacific. Historically, countries around the world recognized four of the five oceans, excluding the Southern Antarctic Ocean from the count. The International Hydrographic Organization recognizes this ocean, which extends into the southern waters beyond Antarctica, as a distinct body of water, although its boundaries remain disputed.
Of the five oceans, the Pacific, Atlantic and Indian oceans cover the largest areas of water, respectively. Together, these bodies of water comprise just over 70 percent of the earth's surface. They feature distinct boundaries, creating cultural, geographical, political and scientific borders. Each ocean contains tributaries and key waterways and provides numerous benefits, including enabling transportation and commerce. They cover vast areas, too: even the third-smallest Indian Ocean spans a distance over five times the size of the United States. The Indian Ocean divides Africa, Asia, Australia and the Southern Antarctic Ocean. It contains unique currents that flow counterclockwise in the southern sphere and clockwise in the northern section.
The Indian Ocean supports a variety of marine life, including endangered species such as seals, turtles and whales. Even the smallest and shallowest ocean, the Arctic Ocean, provides crucial benefits. It covers parts of Eurasia and North America, forming geographical boundaries with Norway, Russia, Greenland, Canada and the United States.