Is the oceanic plates lie under the beach?

No, oceanic plates do not lie directly under the beach. Beaches are typically situated on continental crust, which is the landmass that extends from the shoreline to the continental shelf. Oceanic plates are located beneath the ocean and consist of denser, younger material compared to the continental crust. The transition from continental crust to oceanic crust occurs at the continental shelf, which is generally offshore from the beach.