The dinghy slips away from the first pier of Marina Piccola and the city’s rooftops shrink behind you; granite cliffs and scrubby maquis draw nearer as the boat threads between small coves. The skipper eases the throttle, and the Mediterranean opens—water so clear it reads like glass, edges of Posidonia meadows visible beneath the surface. Stops at Sella del Diavolo, Cala Fighera, Cala Bernat and Cala Mosca offer shallow reefs and short swims, while the canopy of the boat provides shade for those who prefer to watch the water lap by.