A breachway is defined as the shore along a channel. Today the term is used to describe the whole area around where a channel meets the ocean. The Rhode Island

Rhode Island

The state of Rhode Island and Providence Plantations, more commonly referred to as Rhode Island , is a state in the New England region of the United States. It is the smallest U.S. state by area...

 coastline has many breachways on its map

Map

A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....

. Today's permanent breachways have rock

Rock (geology)

In geology, rock or stone is a naturally occurring solid aggregate of minerals and/or mineraloids.The Earth's outer solid layer, the lithosphere, is made of rock. In general rocks are of three types, namely, igneous, sedimentary, and metamorphic...

  jetties that line the sides of the channel to protect against erosion

Erosion

Erosion is when materials are removed from the surface and changed into something else. It only works by hydraulic actions and transport of solids in the natural environment, and leads to the deposition of these materials elsewhere...

 or closing of the waterway. The water

Water

Water is a chemical substance with the chemical formula H2O. A water molecule contains one oxygen and two hydrogen atoms connected by covalent bonds. Water is a liquid at ambient conditions, but it often co-exists on Earth with its solid state, ice, and gaseous state . Water also exists in a...

 channels usually lead to salt water ponds.