[jfoster]

How could that even work? In some areas, surely the Pacific Ocean is deeper than any humans or deep ocean vehicles have ever been to? So would the cable be hanging across undersea chasms, or do they need to find a depth where it can be placed?

Also, is it just so heavy that it doesn't need to be secured?

[Retric]

Deep sea cables don’t need to be secured to anything in the middle they are really heavy and the water isn’t moving quickly.

People setup undersea telegraph cables the 1800’s. This is similar technology just with a thicker cable to carry more current etc. https://en.wikipedia.org/wiki/Transatlantic_telegraph_cable