You can see an undersea cable map here. I don't know about cables specifically but: 1. Anything sea based tends to be cheaper than land based, both in terms of

You can see an undersea cable map here. I don't know about cables specifically but: 1. Anything sea based tends to be cheaper than land based, both in terms of sea transport and also lack of other interfering infrastructure, homes etc along the way 2. Shorter distance means lower latency 3. There surely is a land cable too. There's a lot of redunancy in the system https://www.submarinecablemap.com/ https://www.submarinecablemap.com/