Once you enter the area, walk down the hallway and collect the few clue bottles by the door. Watch out, as the hallway is littered with moving yellow lasers. Once exit the hallway and come out into the large open room, collect the single clue on the right.
The room is filled with security, with a flaming skull shooting lasers that follow you. There are also small laser fences blocking the steps. Make your way around them and then smash the alarm to shut them off. On both sides of the room are three clues. Three are found on the left near the water, while the other three are found by the vault. There is one more clue on top of the flaming skull. Maneuver your way up there to collect it.
Continue pressing on proceed through the dock while laying a smack down on a couple of walruses. Smash the safes to reveal more clues. Then cross the water by jumping on the lily pads until you approach a ladder. This part is trickier, as you have to wall sneak in the right direction while avoiding the lasers blocking the path. On the ledge at the end are a couple more clues. Collect these and head back to the vault to crack it. After that, make your way back to the walkway and grab the treasure key.