Sheer walls dropping past 45m with 35m visibility, caves and tunnels through the rock, dense gorgonians, dentex and amberjack…Sheer walls dropping past 45m with 35m visibility, caves and tunnels through the rock, dense gorgonians, dentex and amberjack, plus the mastic-scented villages ashore. Regularly rated the best diving island in Greece by people who dive there, and ignored by everyone else. Chios grew rich on mastic, the resin that grows nowhere else on earth in commercial quantity, and the Ottomans guarded the trade so jealously that the island was spared and then, in 1822, massacred. The medieval mastic villages of Mesta and Pyrgi survive intact. Anchorage: Anchor off Chios or in the Oinousses channel; the island is a rarely used cruising ground. Hazards: Meltemi wind closes the outer sites; walls drop deep, so depth discipline matters. Plus