The screenies in-game are done with the <Ctrl> <F11> keys combination. Don't hold the <F11> down too long, or you end up with a series of pix that all look the same...
Now, when you say 'everytime I restart I don't get the Nautilus', you're talking about career starts, correct? That would be understandable, with a 50 - 50 chance for one of two boats. However, if you're referring to between missions in a career, the boat should not be changing...