 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 ().Smaller locks at Bougival and at Suresnes lift the vessels to the level of the river in Paris, where the junction with the Canal Saint-Martin is located.