Big Tech and the AI investment boom in underwater cables

More than 95% of international data traffic and voice calls travel over approximately 1 million miles Underwater communications cables.

These cables carry government communications, financial transactions, email, video calls and live broadcasts around the world.

The first commercial undersea telecommunications cable was used for telegraphs and was laid across the English Channel between Dover, England and Calais, France in 1850.

The technology then evolved into coaxial cables that carried telephone conversations and, more recently, optical fibers that carried data and the Internet as we know it.

“About ten years ago, we saw the emergence of another big category, which was web players and their ilk dead, Google, Amazonetc., which now represents probably 50% of the total market,” said Paul Gabla, chief sales officer at Marine Alcatel Networks.

Alcatel is the world’s largest manufacturer and installer of submarine cables, according to industry trade magazine Submarine Telecoms Forum.

Demand for submarine cables is growing as technology giants race to develop computationally intensive processes artificial intelligence Models and connects their growing networks of data centers.

Investment in new submarine cable projects is expected to reach about $13 billion between 2025 and 2027, nearly double the amount invested between 2022 and 2024, according to TeleGeography, which provides communications data.

Amazon also recently announced its first wholly owned company Undersea cable A project called Fastnet.

The Fastnet will connect the Eastern Shore of Maryland to County Cork in Ireland, and will have a capacity of more than 320 terabits per second, which is equivalent to streaming 12.5 million high-definition movies simultaneously, according to Amazon.

“Subsea is really essential to AWS and to any international connectivity across oceans,” Matt Reeder, Amazon Web Services’ vice president for core networks, told CNBC in an interview about Amazon’s investments in subsea cables. “Without Subsea, you would have to rely on satellite connectivity, which can work. But satellites have higher latency and higher costs, and you can’t get enough capacity or throughput to meet the needs of our customers and the Internet in general.”

Google is another big player, having invested in more than… 30 submarine cables.

One of the company’s latest projects is the Sol project, which will connect the United States to Bermuda, the Azores and Spain.

Microsoft It also invested in infrastructure.

“You’ve seen this tremendous growth in submarine cables over the last 20 years,” says Matthew Mooney, global issues director at cybersecurity firm Recorded Future. “And that’s just driven by the insatiable demand for data.”

In September, a break occurred in submarine cables in the Red Sea Disturbances To Microsoft Azure cloud service. The company was able to redirect traffic, but users in Asia and the Middle East were still experiencing increased response time issues and performance degradation.

The majority of submarine cable damage is accidental, usually caused by fishing activity or a ship accidentally dropping its anchor on the cable, experts said. But recently, these cables have become suspicious targets for vandalism.

“When you have that many ships in international waters that are heavily trafficked by a lot of commercial vessels or fishing vessels, the potential for accidents is fairly high,” Murphy said. “But if you’re a hostile actor, you know that too. So, if you’re sending out what’s called a Russian ghost fleet, or if you have a Chinese fishing vessel and the cable accidentally cuts, you can just say, ‘Oh, well, it was an accident.’ But it can be intentional. So it’s really difficult sometimes to determine whether an act of harm was intentional or accidental.”

Mooney and Recorded Future tracked down some cases of suspected vandalism.

“I would say we’ve seen a significant uptick in what we consider intentional damage,” Mooney said. “In 2024 and 2025, [we] There has been a marked increase in incidents in the Baltic Sea and around Taiwan. So it’s difficult to be able to determine with 100% certainty that these things are intentional. However, the patterns of facts that emerge from these events give you reason to doubt that they can all be considered accidental.”

Mooney said the increase in suspected sabotage corresponds with increased tensions between Russia, Ukraine, China and Taiwan.

Although there is no concrete evidence of submarine cable sabotage, governments take the threat seriously.

In January, NATO launched “Baltic Sentry” following several cable outages in the Baltic Sea. The operation involves deploying drones, aircraft and undersea ships to protect undersea infrastructure in the area.

“As a result, I don’t think we’ve seen any cable cuts since late January 2025, in the Baltic Sea,” Mooney said.

The FCC is also taking steps to make sure the devices themselves are not compromised, which would not allow Huawei to do so, Carr said. ZTE Or other questionable “spy equipment” for use in submarine cables.

In July, three House Republicans I sent a message To the CEOs of Meta, Amazon, Google, and… Microsoft Asks whether companies have used PRC cable maintenance providers.

In response to CNBC’s question about the letter, Meta’s Aime said: “We are not working with any Chinese cable system providers on the systems we announced, and we are fully committed to US policy regulations on ecosystem partners and supply chain.”

Amazon also told CNBC that it does not work with Chinese companies.

Microsoft and Google did not respond to CNBC’s request for comment on the letter.

To understand how submarine cables work, CNBC visited Alcatel Submarine Networks’ submarine cable manufacturing facilities in Calais, France, and Greenwich, England. We also spoke to government officials and tech giants to find out why undersea cables are so important to keep us connected and what we can do to protect this critical infrastructure.

a witness video To get the full story.