The five named oceans of the world are the Atlantic, Pacific, Indian, Arctic and Southern Oceans. In reality, Earth is covered by one global ocean.
The global ocean covers 71 percent of the Earth but has been divided into several distinct geographical regions. The Arctic Ocean is the smallest — about the size of Russia — and covers an area of about 5,427,000 square miles. The Pacific Ocean, on the other hand, is the largest and covers 63.8 million square miles, which is about 40 percent of Earth's surface.
The newest of the five oceans is the Southern Ocean. The boundaries of this ocean were proposed in 2000 and include all waters below 60 degrees south.