isolated danger mark
/ˈaɪsəlˌeɪtɪd ˈdeɪndʒə ˈmɑːk/
n
English · isolated danger mark中文 · 孤立危险物标志Español · señal aislada de peligroFrançais · marque de danger isolé
意味：Buoy marking an isolated danger zone beyond which the waters are navigable.