Your Messages Travel Underwater

Right now, your messages are at the bottom of the ocean. Send a text to another continent and it does not fly up to a satellite, whatever the films have taught you. It dives. Almost all traffic between continents travels through cables lying on the sea floor, past shipwrecks and deep sea trenches, in the permanent dark. Send this to the person you message across an ocean.

Each cable is surprisingly modest, often about as thick as a garden hose. Inside, protected by layers of steel and plastic, run thin glass fibers that carry your words as flashes of light. Special ships lay them slowly across entire oceans, and the routes are planned the way roads are planned, around underwater mountains, away from fishing grounds, avoiding places where the seabed likes to move.

The system has enemies, and the most persistent ones are not spies but sharks and ship anchors. Cables get bitten, snagged and buried, and when one breaks, a repair ship sails out, hooks the cable off the seabed, hauls it up and splices the glass back together in a floating workshop. So tonight, when you message someone far away, picture the journey. Your words just crossed an ocean floor, as a flash of light in a glass thread.