Jetty

Made of jet, or like jet in color.

A part of a building that jets or projects beyond the rest, and overhangs the wall below.

A wharf or pier extending from the shore.

A structure of wood or stone extended into the sea to influence the current or tide, or to protect a harbor; a mole; as, the Eads system of jetties at the mouth of the Mississippi River.

To jut out; to project.

a protective structure of stone or concrete; extends from shore into the water to prevent a beach from washing away