Here's a phone call between US President Lyndon B. Johnson and Sealab 2 who were doing just that: https://www.youtube.com/watch?v=wusrtGfjzZg https://www.youtu

Here's a phone call between US President Lyndon B. Johnson and Sealab 2 who were doing just that: https://www.youtube.com/watch?v=wusrtGfjzZg https://www.youtube.com/watch?v=wusrtGfjzZg