There are different reasons why a shoreline can change, including tides. But I've found a phenomenon that I can't explain.
It happens in a Mediterranean beach called L'Esparrelló/La Caleta (link to Google Maps). The central part on this beach (maked in blue in the image below) is closed by two rock promontories (marked in red). The thing is, sometimes you can access to the beach without get into the water from point A but not from point B, and sometimes it's the opposite.
Sometimes one promontory closes the beach and sometimes it is closed by the other. Last summer, for instance, the Google Maps image was accurate: You could access the beach from point B, but not from point A. This summer, it's the opposite: It's not possible to access the beach from point B without getting wet, but it is possible from point A.
I have not observed any change in the amount of sand.
What explains this?