1. On the main deck of the ship after you land, run behind the control tower and 
to the right to find the briefcase on a platform on the side of the ship.

2. In one of the hangars, you have to operate one of the planes to blow through 
a door (a heavy armored guard appears once the door is blown). Search around the 
wall closest to the door. The briefcase is behind some missiles.

3. In the final hangar, after activating the missiles to sink the ship, look 
around the back right of the hangar to find a basketball court. The briefcase 
is behind the basketball hoop closest to the hangar wall.