Almost everything you think of as "the cloud" is actually a few hundred strands of glass lying on the seafloor, unarmoured, in the dark. The physical internet between continents is thinner than your wrist — and about two hundred times a year, something cuts it.
In the deep ocean a transoceanic cable is about 20 mm across — the width of a garden hose. Most of that is steel wire, copper and polyethylene wrapped around a core of optical fibres, each roughly the diameter of a human hair.
Enough to reach the Moon and back — about 3.9 times over (computed from a 384,400 km mean lunar distance).
Tracked worldwide by TeleGeography as of 2026, from 100 km island hops to the 45,000 km 2Africa ring.
Up 23% in a single year, a 24% compound annual rate since 2021. Africa grew fastest, at 38% a year.
Cables are ploughed one to three metres into the seabed where trawlers and anchors work. Past roughly 1,500 metres, burial stops being worth it — from there to the abyssal plain the cable is laid bare on the mud, which is also the only place it is genuinely safe.
In 1858 the first transatlantic telegraph carried a 98-word greeting from Queen Victoria to President Buchanan; it took about sixteen and a half hours to arrive. The same ocean crossing now moves that much text in well under a nanosecond.
Cable routes are not spread evenly across the ocean. They gather at narrow, shallow, heavily trafficked corridors — the Red Sea, the Luzon Strait, Malacca, the Baltic — where a single dragged anchor can sever several systems at once.
Across fifteen years of repair records the picture barely moves: about 199 faults a year, and the overwhelming majority are a fishing net or an anchor meeting a cable that happened to be in the way.
The entire planet's cable repair capacity is a small, ageing fleet. When a cable breaks, a ship has to sail out, grapple a 20 mm line off the seabed, splice it, and lower it back. There is no faster way.
Average vessel age about 20 years; 47% of the fleet nears the end of its service life by 2040. A SubOptic-commissioned study puts the renewal bill at $3 billion.
The Hunga Tonga eruption destroyed the country's only international cable. Repair crews replaced about 90 km of it.
Permits, weather and ship availability, not splicing, are usually what set the clock. A routine fibre repair costs roughly $0.5–1 million.
We describe the internet in weather metaphors and build it out of glass, steel and ships. The fragility is not a flaw to be engineered away — a cable is cheap enough to be worth laying and thin enough to be worth cutting. Resilience comes from redundancy, spare routes and enough vessels to fix things quickly. Right now all three are thinner than the traffic they carry.
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