Secca di Costacuti

An open offshore shoal about 5 nautical miles south of Anzio in the open Tyrrhenian, with no island shelter. It sits fully exposed to the long-fetch Scirocco (SE), Ostro (S) and Libeccio (SW) wind-seas and to the open WSW-W sectors that build the biggest swell here. The nearby Capo d'Anzio promontory to the north, with the Nettuno and Torre Astura coast curving round to the northeast and east, meaningfully shadows the N-NE-E quadrant. Being a deep shoal, swell mainly governs whether boats can reach and hold position on the surface rather than conditions down on the wall.