The Seine river

The tidal phenomenon originating in the Atlantic spreads across the English Channel and up the Seine to just upstream of Rouen. This phenomenon is reflected in a flood current at high tide and a ebb current at low tide.

From the sea to Rouen

Ships sail up the Seine, taking advantage of the flowing current, so to speak, “in convoy”. Shallower-draught vessels enter the channel as soon as the current is established, and benefit from it all the way to Rouen. This current can reach 7 knots in places during high tide periods.

A vessel with the maximum authorized tidal draft (around 11 meters) can only navigate the Seine around high tide. It enters the channel shortly before high tide in Le Havre and arrives in Rouen just after high tide.

Ships entering the channel after high water in Le Havre are called “tard de marée”. They have to make the journey to Rouen with the ebb tide slowing them down, resulting in longer journey times and higher fuel consumption. For this reason, it is often in these ships’ interest to wait for the flood current of the following tide.

Merci à Mr MACCUR du GPMR pour la vidéo

Draught: vertical measurement of the submerged part of the vessel, i.e. the depth of water required for the vessel to float.

High tide: time of the tide when the water level is at its highest, otherwise known as “high tide”.

From Rouen to the sea

Ships leaving Rouen inevitably make part of their journey against the current. This is because they encounter the tidal phenomenon and its current regime.

The animation below describes the descent of a deep-draught ship from Rouen to the sea. The vertical line below the ship’s drawing symbolizes its draught. The bluish thickness symbolizing the water varies according to the tidal wave propagating through the Seine. The shaded area represents the relief of the Seine floor.

At the start of the animation, the ship sets sail from Rouen. It progresses on the ebb tide until it reaches a point where it meets the low tide. At this point, the water is just deep enough for the ship to pass through. As the ship continues its progress, the tide rises and depths improve

The Seine pilots set departure times for ships according to their draught, after determining the precise meeting point.

Shallower-draught ships can make the trip at any time.