AI Boom Fuels Record Investment in Undersea Data Cables — The Hidden Lifeline of the Internet

More than 95% of the world’s internet traffic — including financial transactions, government communications, emails, and streaming data — travels through a vast web of nearly one million miles of underwater cables. These unseen highways are the backbone of global connectivity and a critical enabler of today’s artificial intelligence revolution.

Subsea cables have come a long way since the first telegraph line was laid between England and France in 1850. From coaxial phone lines to today’s high-speed fiber optics, the technology continues to evolve — and demand is now skyrocketing. “AI is dramatically increasing the need for subsea infrastructure,” explained Alex Aime, Vice President of Network Investments at Meta. “Without these connections between data centers, even the most advanced AI systems would just sit idle in expensive warehouses.”

The surge in AI model development and global data center expansion is driving unprecedented investment. According to TeleGeography, spending on new subsea cable projects is set to reach around $13 billion between 2025 and 2027, nearly double the amount invested in the previous three years.

Meta, Google, Amazon, and Microsoft — collectively responsible for about half of all subsea cable projects today — are racing to secure bandwidth for their AI ecosystems. Meta’s Project Waterworth, a 31,000-mile, multi-continent system, aims to be the longest subsea cable ever built. Amazon’s Fastnet project will connect Maryland and Ireland, transferring up to 320 terabits per second — equivalent to streaming over 12 million HD movies simultaneously.

“These cables are vital,” said Matt Rehder, Amazon Web Services’ Vice President of Core Networking. “Without them, the internet and cloud computing would have to rely on satellites, which can’t match the speed, capacity, or efficiency subsea systems offer.”

However, this critical infrastructure faces growing threats. In recent years, cable damage — whether accidental or intentional — has disrupted internet access in multiple regions, including the Red Sea and the South Pacific. In some cases, experts suspect sabotage linked to geopolitical tensions in areas such as the Baltic Sea and near Taiwan.

Governments are now responding with increased vigilance. NATO’s “Baltic Sentry” operation, launched in early 2025, deploys drones and ships to monitor undersea infrastructure following a series of cable cuts in European waters. Meanwhile, U.S. regulators have tightened rules on foreign firms building or maintaining cables connected to American networks, citing national security concerns.

The race to secure and expand subsea infrastructure underscores its importance in the global AI buildout. “Every digital interaction — from a video call to an AI computation — depends on these cables,” said cybersecurity expert Matthew Mooney of Recorded Future. “They’re the invisible veins of the modern world.”