While data centers dominate headlines amid mounting local opposition over electricity bills, water use, and zoning fights, Meta has been expanding its infrastructure somewhere far less visible: the bottom of the ocean.

On Sept. 21, the company announced Petal, a roughly 4,300-mile subsea cable connecting the U.S. and France. Meta says the cable, expected to enter service in 2029, will be the first to deliver petabit-scale capacity across an ocean. It will carry 1 petabit per second, or about 125,000 gigabytes per second, double what today’s most advanced transoceanic cables can handle.

According to Meta, that’s enough capacity for three-quarters of the world’s population to stream music at the same time. The company says Petal achieves this with two-core fiber, which fits two light paths inside each strand. That lets Meta double capacity without a proportional increase in power or physical infrastructure.

Projects like this rarely make headlines in an industry fixated on AI models and apps, but they’re what make those products run. Meta’s personal AI agent, Muse, launched Sept. 8 and climbed to No. 1 on Apple’s U.S. App Store within two weeks, overtaking ChatGPT. It did so even as critics questioned how much access the agent needs to users’ email, calendars, and payment accounts. Muse is powered by Meta’s Muse Spark models, and products like it depend on moving enormous volumes of data between Meta’s data centers and its users around the world.

Meta’s subsea cables reach 6 continents

Subsea cables aren’t new territory for the company, which is now valued at roughly $1.85 trillion. Meta has spent the past decade building its presence on the seafloor and says it has invested in more than 20 subsea cable projects. Taken together, those projects touch every continent except Antarctica.

The most ambitious is Project Waterworth, announced in February 2025. Meta says the system will stretch more than 31,000 miles, longer than the Earth’s circumference. It will connect the U.S., Brazil, South Africa, India, and other regions across five continents. Some segments will be laid as deep as roughly 4.3 miles below the surface to protect them from ship anchors and other hazards.

Meta’s 2Africa system, whose core was completed last year, circles the African continent and connects to Europe, the Middle East, and South Asia. Meta says it lands in 33 countries and can reach 3 billion people.

Meta hasn’t built all of this alone. Petal is being developed with Japan’s NEC and Sumitomo Electric Industries, and French telecom Orange is handling the landing on France’s Atlantic coast. Meta has even partnered with rivals. The MAREA cable between Virginia and Spain, completed in 2017, is jointly owned with Microsoft and telecom company Telxius. Increasingly, though, Meta is taking the driver’s seat. Waterworth will be wholly owned by Meta, making it only the company’s third solely owned cable, according to telecom research firm TeleGeography.

These projects don’t come cheap. Meta hasn’t disclosed what Petal or Waterworth will cost, but TechCrunch reported before Waterworth’s announcement that the project could top $10 billion. Even so, cables are a small slice of Meta’s overall infrastructure bill. The company expects capital expenditures of $130 billion to $145 billion this year, nearly double the $72.2 billion it spent in 2025.

With 12-figure budgets and record-breaking construction projects, Meta is betting its infrastructure spending will pay off. Whether it does remains to be seen.

This story was originally featured on Fortune.com