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Global Fiber Internet: How Undersea Cables Connect the World

Date Published:  January 25th, 2024Date Updated:  January 25, 2024

Ever Skyped a friend in Australia, watched a live stream from South Africa, or made a business call to Japan, all in real-time? This seamless connectivity is thanks to the power of global fiber internet, but have you ever wondered how does fiber optic internet work? How deep is fiber optic cable buried? How does internet connect across continents?

Beneath the ocean’s surface lies a complex network of internet cables, an essential component of the internet’s physical infrastructure. These are not just cables; they are the digital age’s lifelines, bridging distant lands with threads of light.

Imagine an underwater highway sprawling beneath the waves, where instead of vehicles, there’s an endless stream of data traveling at the speed of light. Welcome to the world of oceanic fiber optic cables, where every email, video call, and online transaction begins its underwater journey.

We know you’re probably thinking, “Internet cable on the ocean floor? How do you pull that off?” In this post, we’ll dive into the history of internet cables in the ocean and how undersea cables are laid around the world.

A brief history of connecting continents

Before the internet, the world was introduced to a new method of “instant” communication: the telegraph. Developed throughout the 1830s and 1840s by Samuel Morse and others, the telegraph could send electronic signals over wire for long distance communication.

By 1858, the first transatlantic cable — undersea cables running underneath the Atlantic Ocean for telegraph service — connected Newfoundland with Ireland. Despite early setbacks, including the short-lived functionality of this initial cable, it set the stage for a revolutionary way of communication.

By 1866, persistent efforts finally paid off with the successful installation of a durable transatlantic cable. This was a pivotal moment in communication history: what once took weeks for messages to cross from Europe to North America was reduced to mere minutes. It marked a significant leap from prolonged, uncertain communication to almost instant connectivity.

The landscape of global communication underwent another major transformation with the burst of innovation in the fiber optic technology space in the 1980s. Using light to send data through glass cables, messages could be received instantly.

The debut of TAT-8 in 1988 marked the first transatlantic fiber-optic cable or the first time we put internet in the ocean! Thanks to global fiber technologies, today’s transatlantic cables are capable of transmitting terabytes of data every second. You’re able to read this post thanks to internet connected by undersea cables. They form the robust backbone of our global digital communication network, seamlessly connecting continents.

To learn more about what fiber internet is, fiber internet installation, the benefits of fiber, and more, check out our blog posts on the internet’s latest technological innovation!

Connecting the world, one cable at a time

The process of laying fiber optic cables across the ocean floor is an intricate and fascinating engineering feat. It’s a journey that combines advanced technology, meticulous planning, and precise execution. Here’s a look at how this incredible task is accomplished:

Planning and route mapping

Before a single cable is laid, extensive planning is required. This involves mapping the ocean floor, identifying the most efficient and safest routes. Factors like underwater terrain, environmental concerns, and geopolitical considerations all play a part in plotting these paths.

Manufacturing the cables

Fiber optic cables are specially designed for their underwater journey. These internet cables worldwide are made of thin glass fibers covered in plastic layers, with added protection for underwater conditions, pressure, and dangers.

Loading and transporting

Once manufactured, these cables are wound onto huge drums and loaded onto specialized ships equipped for the laying process. These ships are fitted with sophisticated navigation and cable-laying equipment.

Laying the cables

Transporting an internet cable across the ocean floor is a slow and steady process. The ship releases the cable into the water, gradually unspooling it from the large drums. The fiber optic cable sinks to the ocean floor, guided by its own weight and the ship’s precise navigation.

Navigating varied terrains

As the ship progresses, the cable must navigate various underwater terrains, from flat abyssal plains to mountainous mid-ocean ridges. Remote-operated vehicles (ROVs) are often used to lay cables in particularly challenging areas, ensuring accurate placement and avoiding environmental damage.

Burial for protection

In shallower areas, where cables are more vulnerable to fishing activities, ship anchors, or natural disturbances, they are often buried beneath the seabed for protection. Specialized ploughs, towed by the ship or operated by ROVs, are used for this burial process.

Testing and repairs

After the cable is laid, it undergoes extensive testing to ensure functionality. If any section of the cable is damaged or faulty, repair ships are dispatched to retrieve, fix, or replace the affected segment.

Connecting continents

The final step is connecting the cable to the landing stations on shore. These stations are the link between the undersea cable network and the terrestrial fiber optic networks, completing the global connectivity chain.

The laying of fiber optic cables is a testament to human ingenuity and technological advancement. It’s a process that quietly unfolds beneath the ocean’s surface, enabling our digitally connected lifestyle above.

Visualizing the undersea network

For those visually inclined, take a look at this undersea cable map. Created by TeleGeography, the Submarine Cable Map is a free and regularly updated resource available to the public. Click a cable on the map to learn how long it is, who owns it, what it’s landing points are, and more.


In this vast digital world, it’s easy to forget the marvels that enable our daily binge-watching, endless scrolling, and instant messaging. The importance of global fiber internet can’t be overstated; it’s what makes the world wide web go round!

Every byte of data you send or receive has possibly embarked on an incredible underwater journey, thanks to the network of ocean internet cables.

Curious about high-speed internet? Dive into EarthLink’s world of fiber internet and experience seamless connectivity like never before!

Call 866-618-0397 to get started today!

Maddy Hogan

Maddy Hogan

Maddy Hogan, a copywriter for EarthLink, is a New Englander by birth, raised in the South, and a Hoosier at heart. A graduate of Indiana University-Bloomington's Media School, she brings her unique voice and insights to publications like The Island Packet, The Cherokee Tribune, The Atlanta Business Chronicle, and The Marietta Daily Journal. When she's not writing, Maddy is passionate about traveling, art, reading, movies, well-timed memes, and her two kitties.

See all posts from Maddy Hogan.