Level 18. Floating Fortress (2)

On the boat at the start of the level, move it to the right side platform. Interact with the switch behind the crates to activate a sliding door. Jump onto the tallest crate, then to the other side. From there, jump onto the crates on the opposite side, and then onto the sliding door. The door will transport you to a chamber. Destroy the cracked wall and shoot the switch inside for items.

Before the Serpent Boss, locate a corpse dressed in blue. Stand facing the corpse with the window behind it. Move backward and crouch. You should find a spot to dive down to obtain a medikit.

In the weapons department, aim the turret to face west. Exit the turret, jump onto the cannon, walk along the barrel, and jump into the air vent.

Inside the lower level of the naval vessel, in the bedroom featuring the "Jolly Roger" pirate flag, check the D. Jones locker and the wall within. This will lead you to another room. Interact with the girl for an item, and open the "C. Hook" locker to find a guardian head.

Interact with the PC monitor in the power room. A control panel will open in the opposite room, revealing some items.

In the room after the rail gun turret, proceed up the ramp. You will notice a small gap in the floor containing items. Destroy the wall directly above this gap to enlarge it. Then, crouch and walk against the wall. The resulting blast should widen the gap sufficiently for you to drop down and collect the items.