Snake's Revenge/Part 2

The Dock
You will find yourself outdoors again, at the port. You will receive a call from Nick, who will inform you that John should be aboard the ship. All you have to do in this area is to go north, eliminating the enemies you encounter. Nothing complicated. As soon as you get on the ship, it will start moving and you will never be able to go back.

On the ship
On the first screen, go left. Open the top door with Pass Card 2 to fill up on truth gas. Then go back to the first screen and this time go right. Open the door with Pass Card 2 and enter. Open the door to the north to free a prisoner, who will tell you that John is somewhere else and that there is something important on the bottom of the ship. Exit and go right. Open the door on the right with Pass Card 1 to stock up on grenades. Go north and open the door you find with Pass Card 1. Force the hostage to talk to the truth gas and it will tell you that the Metal Gear has no weak points and will suggest you sink the ship. Exit, go right and open the door at the bottom with Pass Card 2 to go back outside. Go north and open the door at the bottom with Pass Card 2 to stock up on plastic explosives. With that done, go left and then south. You can ignore the door on the right for now. Head south again to return to the first screen and this time enter the grate to the north. Use the elevator to go down to the floor below (going lower is useless for now). Go right and then north, ignoring the door on the left for now. On the next screen you will receive a call from the pilot. Then go left. Open the door at the bottom to find a flare gun. Then go back and this time go right. First open the south door with Pass Card 2. You can start collecting claymore mines. Finally, open the door to the north with Pass Card 1 and prepare yourself for a tough battle.