Sparrow asks this rahter rhetorical question to Miss Elizabeth Swann Keira Knightley] when she starts burning all the rum to make a signal for the British Navy so that she and Sparrow could be rescued.
b: 'Why is the rum gone?' by Captain Jack Sparrow of course!
2: Because that signal is over a thousand feet high. The entire royal navy is out looking for me, do you think there is even the slightest chance they won't see it?
2003: Elizabeth Swann "Pirates of the Caribbean: The Curse of the Black Pearl"
See Also: But why is the rum gone?