Seine Commercial craft (barges and push-tows) can use the river from Marcilly-sur-Seine, to its mouth. At Paris, there are 37 bridges. The river is only above sea level from its mouth, making it slow flowing and thus easily navigable. The Seine Maritime, from the English Channel at Le Havre to Rouen, is the only portion of the Seine used by ocean-going craft. The tidal section of the Seine Maritime is followed by a canalized section ("Basse Seine") with four large multiple locks until the mouth of the Oise at Conflans-Sainte-Honorine (170 km). Smaller locks at Bougival and at Suresnes lift the
Layout of the Port of Tianjin several small barge wharves, but it is planned to expand as part of the development of the Binhai Tourism Area. There are two service wharves planned, 230 m and 150 m in length, plus a large environmental monitoring base, passenger terminal, construction materials wharves and yachting marina. The Beitang Fishing Harbor is directly north, inside the river estuary. The Dagukou Port Area () lies on the southern side of the Haihe river mouth. It is composed of the wharves of the Tianjin Lingang Harbor Economic Zone (), which is a large industrial area being constructed on reclaimed land. The Dagukou