Most people these days seem to insist that all telecom (phone, internet in particular) go overseas by way of satellites. This however is far from the truth. There are actually many trans-oceanic cables and they provide most of the capacity. Mail Online has a great article about what goes into keeping the continents connected.
It’s a whole secret industry, partly for security reasons who in a low-key way keep critical communication between entire continents moving. Most people aren’t even looking at the water, they look up at the sky.