It's a portage!
portage.
river
A strait is a narrow channel of the sea joining two larger bodies of waterAn Isthmus is a relatively narrow strip of land (with water on both sides) connecting two larger land massesOne is a thin bit of water between two big bits of land (that is a strait) whereas the other is a thin bit of land between two big bits of water (that is an isthmus).
A river is a large stream of fresh water that flows across land and empties into an ocean, lake, or some other body of water.
A river or a stream fits this decription...
On Land
A watershed is an area of land that drains to a common body of water.
A lake generally overflows at a location where the surrounding land is lowest.
Island body of land with water around it
Island body of land with water around it
An island is a body of land completely surrounded by water.
A gulf is a large body of water that is partially enclosed by land, with a narrow opening connecting it to the ocean or another body of water. Gulfs are usually deeper and larger than bays. They can be found along coastlines around the world.