An underwater communications cable is a transmission line that crosses the ocean to provide long-distance communications between countries and continents.
The first telecommunication cables, like the one that Sandford Fleming hoped to complete in the late nineteenth century, carried telegraphic messages. Fleming wanted the cable to be used to disseminate news throughout the colonies of the British Empire so that information would circulate more quickly. Later, the development of the telephone brought a new generation of cables adapted to its technology.
Today, underwater cables are made of fibre optics and carry both telephone conversations and electronic data, including Internet data.
Except for Antarctica, every continent is linked to the others by underwater cable.