Baïne

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.

The French term baïne is typical for the Aquitaine coast of France in the departments of Gironde, Charente-Maritime and Landes, 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.

The swell moves the sand along the shore, interfering with current perpendicular to the beach.

Baïnes
Baïnes: Warning sign at Mimizan
The waves feed with water (small red arrows). Water flows out in a strong lateral stream (blue arrow).
Beginning of a baïne