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
History of the Port of Tianjin 1318 the first recorded aid to navigation in the region was established in the Longwangmiao temple at the Haihe mouth. During daytime, white cloth flags were raised on high poles. At night, lamps were lit and raised to guide approaching boats. Activity diminished with fall of the Yuan and the move of the capital to Nanjing. The port of Zhigu was renamed "Tianjin" ("Ford of the Emperor") in 1400 by the Yongle Emperor, to commemorate a victorious forced river crossing. Yongle's move of the imperial capital back to Beijing in 1405 renewed Tianjin’s importance as a grain hub. Soon, the