Submarine Communications Cable

technology · ocean · internet · engineering

Cables on the seafloor. Submarine communications cables are laid on the ocean bottom between countries to send phone calls, text messages, and internet data across oceans. These cables make it possible for people on opposite sides of the world to talk instantly.

Surprisingly thin and strong. These cables are actually thinner than a garden hose, about the width of your thumb. They are made of special materials and protection layers to survive salt water, pressure from the ocean, and even fishing nets that might drag across them.

Light travels through them. The cables carry information as pulses of light that travel through glass fibers at incredible speeds. This is why your video call with someone thousands of miles away feels almost instant.

Tricky to repair. When cables break (from ship anchors, earthquakes, or other accidents), repair ships have to find the exact spot on the ocean floor and fix it underwater. It can take weeks and costs millions of dollars to repair just one break.

Covering the whole planet. Thousands of submarine cables crisscross under the oceans, connecting every continent. Without them, the internet as we know it would not exist.