britannia royal naval college celtic mythology chief petty officer commander corvette county cork ensign eritrea european community exclusive economic zone fenit haulbowline history of the irish naval service irish air corps irish army irish army reserve irish coast guard irish defence forces irish naval service commissioned rank insignia irish naval service enlisted rank insignia irish language leading seaman lieutenant lieutenant commander maritime institute of ireland mary robinson motor torpedo boat mowag piranha naval service reserve naval mine navy petty officer republic of ireland reserve defence forces royal navy setanta ship prefix tralee warrant officer world war ii