Sargasso Sea
The Sargasso Sea is the only sea without any land boundary.
The Gulf Stream establishes the Sargasso Sea’s western boundary, while the Sea is further defined to the north by the North Atlantic Current, to the east by the Canary Current, and to the south by the North Atlantic Equatorial Current. Since this area is defined by boundary currents, its borders are dynamic, correlating roughly with the Azores High Pressure Center for any particular season.