The Internet's Seabed: Submarine Cables, When They Were Laid, Who Owns Them and Where They Crowd Together

Almost all intercontinental internet traffic travels through fibre-optic cables on the sea floor. I describe the network as recorded in TeleGeography's Submarine Cable Map, the most widely used open record of it, in its 2026 version: 608 cables in service with a combined length of 1,592,824 km and 105 planned cables with 502,770 km more, landing at 1,928 points in 186 countries and territories. I ask three questions. When was each cable laid? The ready-for-service years show two booms: the dot-com bubble, when 74 of today's cables came into service in 1999 to 2001, and the present, with a record 32 new cables in 2023 and 49 planned for 2027. Who owns the new cables? Matching owner names shows that Google, Meta, Amazon and Microsoft part-own none of the length ready before 2010, 24% of the length ready in 2015 to 2019, 50% in 2020 to 2026 and 55% of the planned length. Where does the network squeeze through? Counting cables whose routes cross bands drawn across straits and enter hub areas, 18 cables in service cross the Strait of Sicily, 12 pass the Bab el-Mandeb with a combined length of 217,777 km, and 38 reach the sea within 35 km of Singapore. At the other end, 17 islands with no land border depend on a single international cable. The record has no capacities and omits retired cables, so it describes the geography of the network, not its traffic. Interactive version: https://maps.tristanhotham.com/submarine-cables/. Data and code: https://github.com/Tristan-Hotham/submarine-cables. Blog post: https://blog.tristanhotham.com/2026/10/31/submarine-cables/. Data: TeleGeography Submarine Cable Map (submarinecablemap.com), licensed CC BY-NC-SA 3.0; the derived data, figures and text are shared under CC BY-NC-SA 4.0, a later version of the same licence, as 3.0 permits. Code: MIT. Land and borders: Natural Earth (public domain).