There are high voltage submarine cables for electrical power - these are used to cross rivers and lakes, for example. International cables, like the ones betwee

There are high voltage submarine cables for electrical power - these are used to cross rivers and lakes, for example. International cables, like the ones between the UK and the European mainland, are used for load balancing. As it's difficult technically to transmit electrical power over a subsea cable (and exponentially more difficult at the length increases), these cables have limited application. There's over a million kilometers (~600,000 miles) of fiber optic communications cable around the world right now, and perhaps a thousand or so miles of power cable, so "submarine cable" without any qualifier almost always refers to communications cables. https://en.wikipedia.org/wiki/Submarine_power_cable#Operational_submarine_power_cables https://en.wikipedia.org/wiki/Submarine_power_cable#Operatio...