The Indian Ocean is the no. 3rd contiguous open water surface on earth. It has a huge, 26,469,500 square mile (68,556,000 square km) area and 13,002 square feet (3,963 square meters) average depth. The Indian Ocean’s greatest known depth is 24,46 feet (7,455 meters), which can be found at Sunda Trench.
The Indian Ocean is the third largest of the world’s five oceans (after the Pacific Ocean and the Atlantic Ocean, but larger than the Southern Ocean and the Arctic Ocean).
Four critically important access waterways are the Suez Canal (Egypt), Bab el Mandeb (Djibouti-Yemen), Strait of Hormuz (Iran, Oman), and Strait of Malacca (Indonesia-Malaysia).
The International Hydrographic Organization’s decision to delimit a fifth ocean, the Southern Ocean, removed the portion of the Indian Ocean south of 60 degrees south latitude.
Oceans and shallow seas cover more than two-thirds of the planet, to an average depth of 2½ miles / 3.8 km. The Pacific Ocean alone covers nearly half the globe. The oceans contain about 320 million cubic miles / 1,330 million cubic km of salty seawater, accounting for 97 percent of the water on Earth. Most of this water forms a dark, cold realm deep below the surface, where life is scarce, but the shallow, sunlit waters of coastal seas are some of the world’s richest wildlife habitats.