ensure free passage for shipping(англ. термин взят из кн.: Military Balance 2009. – London: International Institute for Strategic Studies, 2009; контекстуальный перевод Alex_Odeychuk)
freeboard(1. the distance from the water line to the gunwales of an open boat or to the main deck of a decked vessel; 2. the distance between normal water level and the top of a structure or mass that rises out of the water, such as a buoy, dam, or ice floe)
