The Sargasso Sea is the only sea with no land coastline, located within the North Atlantic Ocean.
Instead of being enclosed by continents, the Sargasso Sea is defined by ocean currents. The North Atlantic Current, Gulf Stream, Canary Current, and North Atlantic Equatorial Current form its shifting boundaries. These currents create a large rotating system known as the North Atlantic subtropical gyre.
The sea is named for Sargassum, a brown floating seaweed that forms extensive mats at the surface. Christopher Columbus wrote about encountering floating vegetation in the region during his 1492 voyage, and the sea later became associated with tales of becalmed ships and mysterious hazards.
The Sargasso Sea supports important marine life. Young European and American eels travel thousands of kilometers to spawn in its waters, although the exact spawning process was difficult to observe directly. Sargassum mats provide shelter and feeding habitat for fish, crabs, shrimp, sea turtles, and seabirds. Its boundaries change with currents and seasons rather than following fixed map lines.