Rain or shine, I'm going to steal my family's book back. And if Raleigh gets in my way... it's on.
― Sly Cooper, determined to claim what is his[src]
After passing through a small cave, Sly Cooper spotted to his right a large gate blocking the path to Raleigh's hideout. Upon making to the other side and past the security, he caught sight of a big blimp, which Bentley concluded to be Raleigh's hideout. Sly, however, pointed out that it looked more like a machine than a hideout, which Bentley agreed with, correctly identifying it as a storm machine and believing it to be the source behind the continuous rainfall and shipwrecks in the area.
Raleigh's desire for continous rainfall at his own hideout made no sense to Sly and Bentley, but regardless, Sly was determined to reclaim what was rightfully his and take Raleigh down if he had to.
The clues have led me to believe that the code for this vault is 7-9-2.