ARABIAN SEA (anc. Mare Erythraeum), the north-west section of the Indian ocean, bounded east by India, north by Baluchistan and southern Persia, and west by Arabia and the "horn" of Africa. It has two important branches—the Gulf of Aden, connecting with the Red sea through the Strait of Bab-el Mandeb; and the Gulf of Oman, leading to the Persian Gulf. The sea, long a centre of coastwise sailing, forms part of the chief highway between Europe and India. Its islands are few and insignificant, the chief being Socotra, off Somaliland, and the Laccadives. The coasts, save for the Indian shore between Bom bay and Karachi, are steeply tilted and fall into deep water.