The world's third largest ocean, situated east of Africa, west of Australia and south of Asia. It dominates 20% of the earth's surface, and surrounds the island countries of Madagascar, Sri Lanka, the Maldives, the Comoros and Mauritius. The Zambezi, Indus, Ganges, Brahmaputra, and Irrawaddy rivers, and the Persian Gulf flow into the Indian Ocean - a natural resource enjoyed by Tanzanian subsistance fishermen, Omani oil shieks, Burmese rice farmers and Australian surfers.

The African, Antarctic, and Indian tectonic plates meet in the Indian Ocean, somewhere south of Mumbai. The continental shelves are narrow (on average about 200 kilometres wide), although off the natural gas-rich Australian coast the shelf width can be greater than 1,000 kilometres wide. The deepest point, the Java Trench goes down to almost 7.5 kms below the water surface.

The northern hemisphere portion of the ocean is blighted by monsoons, travelling northerly from October to April (winter monsoon), and southwesterly at other times, dumping buckets of rain onto India and even unluckier Bangladesh. The monsoons control the currents, which rotate clockwise in the Northern hemisphere and counterclockwise in the south. South of the equator the winds are calmer.

Lines of communication usually skirt along the sides of the Indian Ocean - unlike the Pacific or Atlantic where people are usually only interested in transversing directly from one side or the other. The ancient Egyptians used the Red Sea to get to Somalia, and possibly the Phoenicians reached the ocean as well, but from the time of the Romans to the time of Marco Polo the Indian Ocean was effectively ignored. Foreign cultures were able to spread from continent to continent in pre-Columbian times and beyond, such as by Arab traders travelling down the west coast of Africa or reaching Indonesia, and it also helped Europeans in their colonial quests to put tea on their breakfast tables, courtesy of the Dutch East India Company. Its importance grew after the opening of the Suez Canal in 1869. However the Ocean only saw minimal conflict in both world wars and was largely ignored in the Cold War. Still the United States has a significant presence on the nebulous jurisdiction of the British Indian Ocean Territory of Diego Garcia.

Otherwise the Indian Ocean is pretty much hopeless as a fishing spot - the warm water temperatures is not suitable for phytoplankton production.