Is it possible scientifically to see some day a train travelling between two continents in just less than two hours!!?? Like, submerging in the extreme depths of sea;then diverting and re-emerging with a vary fast buoyant supersonic speed to the other part of the world!!?
Hope it will be interesting to comment on the idea
I expect that water creates too much resistance for that kind of speed. The amount of energy required to pull it off would be insane (not to mention finding a design that would make it feasible were energy generation/cost not an issue).