Here's why:

* Erosion: Sea caves are formed by the erosive power of waves. The constant pounding of waves against the cliff face, particularly during storms, weakens the rock.

* Abrasion: The waves carry sand and other rock fragments that act like sandpaper, grinding away at the rock.

* Hydraulic action: The force of the water itself can create pressure, forcing air into cracks and weakening the rock.

* Solution: If the rock is made of a soluble material like limestone, the slightly acidic seawater can dissolve the rock over time.

Deposition involves the accumulation of material, whereas sea caves are formed by the removal of material.