As one component of the World Ocean, the Indian Ocean is delineated from the Atlantic Ocean by the 20° east meridian running south from Cape Agulhas, and from the Pacific Ocean by the meridian of 146°55' east. The Indian Ocean's volume is estimated to be 292,131,000 km³ . Island nations within the ocean are Madagascar , Bahrain, Comoros, Maldives, Mauritius, Seychelles and Sri Lanka.