Rip current in the Caspian Sea.
https://en.m.wikipedia.org/wiki/Rip_currentA rip current, yagun, is formed at low tide, when the water begins to move (at different speeds) back to the sea.
On the northern and southern coasts, the rip current occurs mainly twice a day, on the western and eastern coasts - once a day.
The amplitude of the rip current depends on the speed of the current along the coast.
And the speed of the current along the coast depends on the amount of water flowing into the Caspian Sea from the Volga River and the direction of the wind along the coast.
Knowing the speed of the current along the coast, it is possible to predict the reverse current with an accuracy of up to a minute.
http://tapemark.narod.ru/more/06.pngThe shallower the coast, the faster the speed of the current along the coast.
In summer, during floods on the Volga River, the amplitude of the rip current is maximum; in spring, autumn, and during drought in the Volga River basin, it is minimal.
The cause of the rip current may also be a storm tide.
https://xn----ptbgks9a.kz/navodneniya/uroki-istorii/item/498-nagonnaya-volna-eto-malenkoe-tsunamiContinuation: Academgorodok Forum Novosibirsk. The science. "Ebb and flow"
https://forum.academ.club/index.php?showtopic=1235578