Anchorage can be obtained close off the harbour in depths of about 14 m, sand, 300 m NE of the head of Molo Santa Barbara; the mole protects the E side of the harbour. The alignment (176°) of the E extremity of L’Isolotto with the E extremity of Colle della Rocca (elevation 106 m, with Forte La Rocca on its summit) on the S side of Porto Ercole, is a useful guide to the anchorage.