Location: body of water between Africa, Asia, Australia, and Antarctica

note: includes Arabian Sea, Bass Straight, Bay of Bengal, Java Sea, Persian Gulf, Red Sea, Straight of Malacca, Timor Sea, and other tributary water bodies

Coastline: 66,526 km

International disputes: some maritime disputes (see littoral states)

Climate: northeast monsoon (December to April), southwest monsoon (June to October); tropical cyclones occur during May/June and October/November in the north Indian Ocean and January/February in the south Indian Ocean

Terrain: surface dominated by counterclockwise gyre (broad, circular system of currents) in the south Indian Ocean; unique reversal of surface currents in the north Indian Ocean, low atmospheric pressure over southwest Asia from hot, rising, summer air results in the southwest monsoon and southwest-to-northeast winds and currents, while high pressure over northern Asia from cold, falling, winter air results in the northeast monsoon and northeast-to-southwest winds and currents; ocean floor is dominated by the Mid-Indian Ocean Ridge and subdivided by the Southeast Indian Ocean Ridge, Southwest Indian Ocean Ridge, and Ninety East Ridge; maximum depth is 7,258 meters in the Java Trench

Natural resources: oil and gas fields, fish, shrimp, sand and gravel aggregates, placer deposits, polymetallic nodules

Environment: endangered marine species include the dugong, seals, turtles, and whales; oil pollution in the Arabian Sea, Persian Gulf, and Red Sea

Note: major chokepoints include Bab el Mandeb, Strait of Hormuz, Strait of Malacca, southern access to the Suez Canal, and the Lombok Strait; ships subject to superstructure icing in extreme south near Antarctica from May to October