re: Living in isolation
During the Cold War, nuclear missile submarines went on missions where they can remained submerged for months at a time. With modern nuclear submarines, the only limits on mission time are food and sanity.
The U.S.S. Triton went completely around the world submerged in 1960, rounding the Horn and the Cape of Good Hope. The definition of submerged was cut a little fine when they broke the surface with the sail to transfer a sick sailor to another ship near Uruguay. The trip took about two months. I still remember the National Geographic article on this as a special favorite.