The baïne is a geographical phenomenon unique to the Aquitaine

Aquitaine

Aquitaine , archaic Guyenne/Guienne , is one of the 27 regions of France, in the south-western part of metropolitan France, along the Atlantic Ocean and the Pyrenees mountain range on the border with Spain. It comprises the 5 departments of Dordogne, :Lot et Garonne, :Pyrénées-Atlantiques, Landes...

 coast of France

France

The French Republic , The French Republic , The French Republic , (commonly known as France , is a unitary semi-presidential republic in Western Europe with several overseas territories and islands located on other continents and in the Indian, Pacific, and Atlantic oceans. Metropolitan France...

 found in the departements of Gironde

Gironde

For the Revolutionary party, see Girondists.Gironde is a common name for the Gironde estuary, where the mouths of the Garonne and Dordogne rivers merge, and for a department in the Aquitaine region situated in southwest France.-History:...

 and Landes. It takes the form of a small pool of water, parallel to the beach, directly connected to the sea. These are spaced every 300 to 400 metres and formed under the influence of waves

WAVES

The WAVES were a World War II-era division of the U.S. Navy that consisted entirely of women. The name of this group is an acronym for "Women Accepted for Volunteer Emergency Service" ; the word "emergency" implied that the acceptance of women was due to the unusual circumstances of the war and...

 and the tide

Tide

Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the moon and the sun and the rotation of the Earth....

. When the tide is receding, they cause a very strong current out to sea. The current will vary depending on the height of the waves and the height of the tide. It is at its strongest and most dangerous, during the final hours approaching low tide and the first hours afterwards.