The Sargasso Sea is unique in that it is the only sea on the planet that does not have any land boundaries. Instead of being enclosed by coastlines, the boundaries of the Sargasso Sea are defined by four ocean currents: the Gulf Stream, the North Atlantic Current, the Canary Current, and the North Atlantic Equatorial Current. These currents act as ever-changing banks of water that enclose the Sargasso Sea’s renowned calm waters and the Sargassum seaweed within the North Atlantic Gyre.