Overfalls are areas of land that extend out to sea as shallow promontories.

They create a sort of sea break that can be invisible apart from the effect they have on the seastate itself.

Tide and wind against them can create standing waves and currents running parallel to them, all of which can add up to some quickly changing sea conditions and surprising changes from calm to rather disturbing.

English and French sailors are particularly aware of Overfalls, having some of the most famously dangerous in the world.

Overfalls are usually marked on charts but not always shown with warnings. In the Med in particular, perhaps because of the lack of strong tides, they are often not marked as a place for caution. BUT caution must still be taken as if the wind and current is pushing onto an overfall, expect to be bounced around at the very least.