Nautilus's ultimate, Depth Charge, seeks out opponents and pops up everything en route, and finally pops up the target when it reaches him. What happens if the target teleports just as Depth Charge is cast? Does it slowly make its way across the map? Does it have a maximum range? If it has a maximum range, is it possible to evade with the likes of Flash? What is the range?
When Xypherous did his Dev Diary for Nautilus he answered this question:
(Forum Goer)Quote: Can you dodge it, or blink over it (referring to the ultimate)?
(Xypherous):If you doge it or blink over it, it will turn around to chase you some more, forever - RUN SINGED RUN.
(Forum Goer) Quote: Master Yi Speed Test Inc.
(Xypherous):I think Rammus stands a better shot of making it halfway across the map before it hits him - :P
(Xypherous):If you can outrun it for 5 seconds or get 2000+ units away from it, it'll just explode on the spot.
Link to the source
Found a video of someone actually managing to outrun Nautilus' ultimate: