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
Seine River Steamers where small steamers take on loads for journey further up river. Continuous improvements to the shipping lane meant that regular traffic could be maintained and not just in periods of high water. In 1840 when the French nation desired the return of Napoleon's body from the Island of St. Helena, to his adopted nation of France, he travelled by sailing frigate to Cherbourg, then to a series of steamers up the river. On 30 November, la Belle-Poule entered the roadstead of Cherbourg, and six days later the remains were transferred to the steamboat la Normandie. Reaching Le Havre, the coffin