You may have never noticed but the things keeping our internet functioning are the oceans. Now, this may sound crazy, but hear me out.
Although it’s not the actual ocean that helps the wifi function, the colossal area of the great oceans engulf the crust of the Earth. Massive, lengthy wires called submarine communication cables run throughout the length of the oceans connecting continents. In fact, about 99% of the data found on the internet travels through a labyrinth of 229 cables at the bottom of the seafloor. These submarine communication cables are no thicker than a soda can and are made up of the same HDMI cables we use. Some of them have steel casings to protect them from the harsh underwater environment.
These wires are laid by specially made ships that can carry over 2,000 km length worth of wires. These ships lay down the cables at the bottom depending on factors like the terrain, weather, etc. They lay about 150-200 km worth of cables per day.
The cables are specially constructed for submarine operations as they have to endure harsh conditions as well as pressure. Fiber optic cables carry DWDM [Dense Wavelength Division Multiplexing] laser signals at a rate of terabytes per second. They use optical repeaters to strengthen the signal which attenuates over long distances.
They have a decade lifespan and costs vary (depending on the length of the cable). The typical cost for a project is anywhere from $100m-$500m. We don't use satellites because they can't carry terabytes of data for