These maps show the density of submarine communications cables around the world. The top map displays unweighted line density, while the bottom has been weighted by bandwidth (e.g., Gbps).
The data come from Greg Mahlknecht’s website (see link below). He states that the accuracy of the layout varies, as he was able to obtain exact routes for some cables, but other routes are schematic depictions based on landings. In addition, he generally excludes cables below 1 Gbps. It should also be noted that some of these cables are defunct, or are not yet activated. So these maps should be considered generalizations of global submarine communications; they are not exact, but provide an overall sense of the layout.
Data source: http://www.cablemap.info/
Via Mathijs Booden