Wirebook › Glossary › Undersea cable
What is an undersea cable?
In one sentence: A cable on the sea floor holding thin glass fibres that carry data between continents as flashes of light.
A little more
Almost all the data that crosses oceans travels through cables on the sea floor, not through space. Inside each cable are hair-thin glass fibres carrying flashes of light, with repeaters every 50 to 100 km to boost the signal.
There are hundreds of these cables. When a ship's anchor breaks one, special repair ships fish up the ends and splice them back together.
It's a bit like… A garden hose for light, thousands of kilometres long, lying on the bottom of the sea.