North Eastern Atlantic

Southwest of Ireland the Celtic Sea gives way to the open Atlantic. The peninsulas of Cork and Kerry project toward these waters, with Mizen Head marking the southwestern end of the Irish mainland. A ship rounding the coast here leaves the shelter of the bays and encounters the long swell of the ocean. These western approaches joined routes from the Irish Sea and the Channel to the Atlantic; landfalls on the Irish coast offered sailors a way to judge their position after a long passage.