The Arabian Sea () is a region of the northern Indian Ocean bounded on the north by Pakistan, Iran and the Gulf of Oman, on the west by the Gulf of Aden, Guardafui Channel and the Arabian Peninsula, on the southeast by the Laccadive Sea and the Maldives, on the southwest by Somalia, and on the east by India. Its total area is 3,862,000 km2 (1,491,000 sq mi) and its maximum depth is 4,652 meters (15,262 ft). The Gulf of Aden in the west connects the Arabian Sea to the Red Sea through the strait of Bab-el-Mandeb, and the Gulf of Oman is in the northwest, connecting it to the Persian Gulf. Geography The Arabian Sea's surface area is about . The maximum width of the sea is approximately , and its maximum depth is . The biggest river flowing into the sea is the Indus River. The Arabian Sea has two important branches — the Gulf of Aden in the southwest, connecting with the Red Sea through the strait of Bab-el-Mandeb; and the Gulf of Oman to the northwest, connecting with the Persian Gulf. There are also the gulfs of Khambhat and Kutch on the Indian Coast. The Arabian Sea has been crossed by many important marine trade routes since the 3rd or 2nd millennium BCE. Major seaports include Kandla Port, Mundra Port, Pipavav Port, Dahej Port, Hazira Port, Mumbai Port, Nhava Sheva Port (Navi Mumbai), Mormugão Port (Goa), New Mangalore Port and Kochi Port in India, the Port of Karachi, Port Qasim, and the Gwadar Port in Pakistan, Chabahar Port in Iran and the Port of Salalah in Salalah, Oman. The largest islands in the Arabian Sea include Socotra (Yemen), Masirah Island (Oman), Lakshadweep (India) and Astola Island (Pakistan). The countries with coastlines on the Arabian Sea are Yemen, Oman, Pakistan, Iran, India and the Maldives. Limits The International Hydrographic Organization defines the limits of the Arabian Sea as follows: On the west: the eastern limit of the Gulf of Aden. On the north: a line joining Ràs al Hadd, east point of the Arabian Peninsula (22°32'N) and Ràs Jiyùni (61°43'E) on the coast of Pakistan. On the south: a line running from the southern extremity of Addu Atoll in the Maldives, to the eastern extremity of Ràs Hafun (the easternmost point of Africa, 10°26'N). On the east: the western limit of the Laccadive Sea a line running