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Wednesday, November 4, 2026Nov 4

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How the internet travels across oceans

Fiber optic cables
Fiber optic cables Fiber optic cables

The internet consists of tiny bits of code that move around the world, traveling along wires as thin as a strand of hair strung across the ocean floor. The data zips from New York to Sydney, from Hong Kong to London, in the time it takes you to read this word.

Nearly 750,000 miles of cable connect the continents to support our insatiable demand for communication and entertainment. Companies have typically pooled their resources to collaborate on undersea cable projects, like a freeway for them all to share.

But now Google is going its own way, in a first-of-its-kind project connecting the United States to Chile, home to the company’s largest data center in Latin America.

“People think that data is in the cloud, but it’s not,” said Jayne Stowell, who oversees construction of Google’s undersea cable projects. “It’s in the ocean.”

Getting it there is an exacting and time-intensive process. A 456-foot ship named Durable will eventually deliver the cable to sea. But first, the cable is assembled inside a sprawling factory a few hundred yards away, in Newington, New Hampshire. The factory, owned by the company SubCom, is filled with specialized machinery used to maintain tension in the wire and encase it in protective skin.

The cables begin as a cluster of strands of tiny threads of glass fibers. Lasers propel data down the threads at nearly the speed of light, using fiber-optic technology. After reaching land and connecting with an existing network, the data needed to read an email or open a web page makes its way onto a person’s device.

While most of us now largely experience the internet through Wi-Fi and phone data plans, those systems eventually link up with physical cables that swiftly carry the information across continents or across oceans.

In the manufacturing process, the cables move through high-speed mills the size of jet engines, wrapping the wire in a copper casing that carries electricity across the line to keep the data moving. Depending on where the cable will be located, plastic, steel and tar are added later to help it withstand unpredictable ocean environments. When finished, the cables will end up the size of a thick garden hose.

A year of planning goes into charting a cable route that avoids underwater hazards, but the cables still have to withstand heavy currents, rock slides, earthquakes and interference from fishing trawlers. Each cable is expected to last up to 25 years.

A conveyor that staff members call “the Cable Highway” moves the cable directly into Durable, docked in the Piscataqua River. The ship will carry more than 4,000 miles of cable weighing about 3,500 metric tons when fully loaded.

Inside the ship, workers spool the cable into cavernous tanks. One person walks the cable swiftly in a circle, as if laying out a massive garden hose, while others lie down to hold it in place to ensure it doesn’t snag or knot. Even with teams working around the clock, it takes about four weeks before the ship is loaded up with enough cable to hit the open sea.

The first trans-Atlantic cable was completed in 1858 to connect the United States and Britain. Queen Victoria commemorated the occasion with a message to President James Buchanan that took 16 hours to transmit.

While new wireless and satellite technologies have been invented in the decades since, cables remain the fastest, most efficient and least expensive way to send information across the ocean. And it is still far from cheap: Google would not disclose the cost of its project to Chile, but experts say subsea projects cost up to $350 million, depending on the length of the cable.

Yann Durieux, a ship captain, said one of his most important responsibilities was keeping morale up among his crew during the weeks at sea. Building the infrastructure of our digital world is a labor-intensive job.

With 53 bedrooms and 60 bathrooms, the Durable can hold up to 80 crew members. The team splits into two 12-hour shifts. Signs warn to be quiet in the hallways because somebody is always sleeping.

The ship will carry enough supplies to last at least 60 days: roughly 200 loaves of bread, 100 gallons of milk, 500 cartons of a dozen eggs, 800 pounds of beef, 1,200 pounds of chicken and 1,800 pounds of rice. There’s also 300 rolls of paper towels, 500 rolls of toilet paper, 700 bars of soap and almost 600 pounds of laundry detergent. No alcohol is allowed on board.

“I still get seasick,” said Walt Oswald, a technician who has been laying cables on ships for 20 years. He sticks a small patch behind his ear to hold back the nausea. “It’s not for everybody.”

Demand for undersea cables will only grow as more businesses rely on cloud computing services. And technology expected around the corner, like more powerful artificial intelligence and driverless cars, will all require fast data speeds as well. Areas that didn’t have internet are now getting access, with the United Nations reporting that for the first time more than half the global population is now online.

“This is a huge part of the infrastructure that’s making that happen,” said Debbie Brask, the vice president at SubCom, who is managing the Google project. “All of that data is going in the undersea cables.”