The gates of the straits, which the Moors call Babelmandem, are exceedingly narrow. They lie in a latitude of twelve degrees and two-thirds, and in the very mouth of the straits there lies an island extended right across it which the Moors call Mium, and on one side stretches the territory of the Preste João called Jazem by the Moors, and on the other lies the mainland of Arabia. Between this island and terra-firma runs a passage or canal about one league only in breadth, through which pass all the ships of the Moors bound to Suez and all the other parts thereabouts, for they come with the east winds, and they lie to on the Arabian side of the land, which forms a very sheltered harbour for them. And in front of this island of Mium, in the same harbour and shelter from the east wind, lies a small islet, to which at low tide one can walk dry-shod on to terra-firma. It is in this island that the Rubães live, who are the pilots of the straits. In the middle of this canal the soundings are about twelve fathoms, and in the harbour sheltered from the east winds the soundings vary from seven to nine fathoms.