A baïne is a pool of water of a few dozen to several hundred metres in length, parallel to the beach and directly connected to the sea. Each one is spaced every 300 to 400 metres and formed under the influence of

waves Waves most often refers to: *Waves, oscillations accompanied by a transfer of energy that travel through space or mass. * Wind waves, surface waves that occur on the free surface of bodies of water. Waves may also refer to: Music * Waves (ban ...

and the

tide Tides are the rise and fall of sea levels caused by the combined effects of the gravity, gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide t ...

. The French term ''baïne'' is typical for the

Aquitaine Aquitaine ( , , ; oc, Aquitània ; eu, Akitania; Poitevin-Saintongeais: ''Aguiéne''), archaic Guyenne or Guienne ( oc, Guiana), is a historical region of southwestern France and a former administrative region of the country. Since 1 January ...

coast of

France France (), officially the French Republic ( ), is a country primarily located in Western Europe. It also comprises of Overseas France, overseas regions and territories in the Americas and the Atlantic Ocean, Atlantic, Pacific Ocean, Pac ...

in the departements of

Gironde Gironde ( US usually, , ; oc, Gironda, ) is the largest department in the Nouvelle-Aquitaine region of Southwestern France. Named after the Gironde estuary, a major waterway, its prefecture is Bordeaux. In 2019, it had a population of 1,62 ...

Charente-Maritime Charente-Maritime () is a department in the Nouvelle-Aquitaine region on the southwestern coast of France. Named after the river Charente, its prefecture is La Rochelle. As of 2019, it had a population of 651,358 with an area of 6,864 square kil ...

and

Landes ''Landes'', or ''Lanas'' in Gascon, means moorland or heath. ''Landes'' and ''Lanas'' come from the Latin ''plānus'' meaning “‘flat, even, level, plain’”. They are therefore cognate with the English plain (and plane), the Spanish word '' ...

, but it can occur on beaches throughout the world. When a wave hits the coast, it can pass over the sandbar that separates the ''baïne'' from the sea and enter it all along its length. When the wave subsequently recedes, the ''baïne'' water is pushed out through the single point where it was connected to the sea. At this point a

rip current A rip current, often simply called a rip (or misleadingly a ''rip tide''), is a specific kind of water current that can occur near beaches with breaking waves. A rip is a strong, localized, and narrow current of water which moves directly away ...

, a very strong offshore current, can occur. 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 Tides are the rise and fall of sea levels caused by the combined effects of the gravitational forces exerted by the Moon (and to a much lesser extent, the Sun) and are also caused by the Earth and Moon orbiting one another. Tide tables can ...

, and in the first hours afterwards. Swimmers caught in this current are advised not to resist but to let themselves be carried out to sea where the current is weaker, then to swim parallel to the beach before attempting to approach the shore. Recommendations by the Wassenaar life guards (Netherlands)

Development of a baïne

Baïnes appear where the phenomenon of

is strong, the

sand Sand is a granular material composed of finely divided mineral particles. Sand has various compositions but is defined by its grain size. Sand grains are smaller than gravel and coarser than silt. Sand can also refer to a textural class of s ...

fine, the beach flat with a strong swell. The swell moves the sand along the shore, interfering with current perpendicular to the beach. These currents prevail seaward the sandy bottom and digging pits visible at low tide of up to 100 meters wide and 4-5 meters deep. Each baïne has its own morphology and generates various forms of currents.

References

Coastal and oceanic landforms {{topography-stub