http://www.fluviacarte.com/fr/voies-navigables/region-bassin-de-la-seine-5/voie-seine-maritime-85 Fluviacarte], Seine maritime 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 kilometers ).