A flying sub :O
http://www.techtimes.com/articles/14147/20140828/chinese-researchers-working-on-a-flying-submarine-shanghai-to-san-francisco-in-100-minutes.htm

something copied from the movie terminator  me thinks
http://www.washingtontimes.com/news/2014/sep/2/pentagons-experimental-phantom-swift-x-plane-contr/

Good articles there Syber 

I suspect the artist had been watching T3: Rise of the Machines the night before making that rendering 

I would  not doubt it 

Bet the sub would be loud and the shape is poor if the bubble collapses. Interesting though.

I reckon the second one's a pipe dream. Looks like the artist has been watching T3 and is a thunderbirds fan (original puppet series not the car).

At the speeds they are suggesting for the sub noise is unlikely to be an issue 

if that bubble pops I'm sure it would wreak havoc on the entire frame to the point of destruction with no survivors. just my theory