The mean depth of the sea is estimated at 133 fathoms. The bora (north-east wind), and the prevalence of sudden squalls from this quarter or the south-east, are dangers to navigation in winter.
Most rain falls between November and May, and at this season the torrents are tremendous while they last, and squalls of wind are frequent and violent, almost invariably preceding a downpour.
The entrance is contracted by Tiran and other islands, so that the passage is rendered somewhat difficult; and its navigation is dangerous on account of the numerous coral reefs, and the sudden squalls which sweep down from the adjacent mountains, many of which rise perpendicularly to a height of 2000 ft.
Sailing is hardly ever practised, and squalls on the lakes are often dangerous to the rowing-boats.