Oh man, I didn't even think of the 'Hungry Like the Wolf' and 'Bad Wolf' connection!
I really enjoyed this episode. The reason it's so scary to me is because I don't like enclosed spaces like that, but anyone who knows me well knows that open water like that is one of my biggest fears (and why I would never go on a cruise). Therefore, the who idea of being in a sub just scares the trout out of me. And then them crashing and all that water leaking in. ;-;
EDIT: I also loved the Professor. He really doesn't have the best luck with maritime travel, does he?