COMPLETE MISSION WALKTHROUGH:
We'll start off inside a moving elevator (#1). Sadly, you won't be able to stay here for too long. You will receive a proper warning from your friends at JBA. You will have to find a hole in the roof. Climb up there (#2) and wait for the elevator to reach a new floor.
One of the guards will enter the elevator. I'd strongly recommend that you jump on him (#1), so you won't have to worry about avoiding him in the future. You could also ignore him, however this would make your mission a lot more difficult. Pick up his body and move it to the left, so it won't be noticed by anyone else. Leave the elevator and start moving towards the pool area (#2). This is one of the most difficult sections of this entire mission, so you will have to be very careful.
Keep moving forward. Stick close to the left wall and make sure that you're using larger objects for cover. Get closer to the guards (#1). You will have to wait for Enrica to hack into the pool area computer system. As a result, some of the sprinklers will be activated. Make a few steps forward. The guards will continue patrolling this area (#2). That's when you'll need to make a move.
Climb up and perform a single jump. You'll end up in the water (#1). As long as you stay here, you'll be quite safe. You will have some serious problems leaving the pool. Wait for the sprinklers to activate. Now you will have to start moving towards the nearby stairs (#2). They are located on your left. Make sure that none of the guards sees you. This would be equal to an instant failure.
Once you've reached the stairs, keep moving upwards (#1). You will have to reach the upper balcony as soon as possible. This is very important, because you're exposed here. Once you're there, use some of the larger objects for cover. One of the nearby tables seems like a good idea (#2). SAVE your game here. You will also have to take a closer look at one of the guards. He is patrolling the balcony, so you must avoid him at all costs.
Keep moving forward (#1). Thankfully, you will have an opportunity to use nearby objects for cover. You could also hide in one of the lockers, however this won't be necessary. Try to get closer to the second large table. After that, you will be able to go to a glass door (#2). Enter the new area. You will also have to avoid a security camera that's located here. You probably won't notice it at first glance. Save the game!
The first thing you have to do here is to flip a switch (#1). This will shut off the lights in one of the nearby rooms. Head on to the right corridor. You will have to be standing in a dark spot. Wait for the guards to leave the main area of the spa (#2). You will have to go there now. Bear in mind that you won't be able to stay here for too long, because the guards will eventually return to their original posts.
Keep moving forward. You will have to climb up to a small ledge. Press the jump key once again (#1). This will allow you to reach the highest platform. Enter the ventilation shaft. You shouldn't have any problems locating it. You will have to crawl through to the next section of the ship. You will be able to reach a small cabin that's being occupied by one of the crew members (#2). Don't leave the ventilation shaft just yet. Instead, save your game.
You could wait for the crew member to leave, however I wouldn't recommend doing that. It's best that you take care of him right away (#1). Thankfully, you shouldn't have any problems knocking him unconscious. Open the door. You've probably noticed that a second opponent is sitting here (#2).
You can resolve this problem using various approach methods. The easiest way to get rid of him would be to grab him. You won't have any problems doing this (#1). Additionally, you could interrogate the crew member. As a result, you would be given a code to the nearby door (2112). If you plan on avoiding him, you would have to distract his attention. Using the ultrasonic emitter seems like a good idea. As for the code, you could acquire it by using a computer or opening a file cabinet (#2).
Make sure that you're not interrupted. You will have to open a glass door (#1). Hack into the system or enter the combination. SAVE your game here and use the stairs to reach the lower level of the ship. This room is being occupied by two crew members. Additionally, one of the guards is patrolling a nearby balcony. I'd strongly recommend that you take these guys out (#2). You shouldn't have any major problems doing that. Avoiding them would be far more difficult, mostly because they're not standing in one spot. Also, you would have to be very careful on the balcony.
If you don't plan on neutralizing these guys, you would also have to use one of your gadgets. Ultrasonic emitter seems like a good idea. You could also use the whistling feature. Either way, you will have to reach the balcony. Perform a single jump and grab the rope (#1). You will have to wait for Fisher to slide down (#2). SAVE your game here. It's very important and you haven't much time to avoid more enemy guards.
Turn around and move to your right. Enemy guards are currently occupying a large building that should be located in front of you. The objective is to get there before they decide to leave the room. Jump over the balustrade (#1) and climb down. Make sure that you're close to the rear side of the structure (#2). You'll be safe here and it's a good spot to plan your next actions.
You will have to get closer to the stairs (on your right). One of the guards will arrive here very shortly (#1). Take him out, mostly because he would have been able to spot you from the upper balcony. Additionally, it would be wise to hide his body. Try moving closer to the entrance. The second soldier will be patrolling this area (#2), so you will have to be very careful. You may try avoiding or neutralizing him.
Once this problem has been resolved, move up closer to the entrance. You will have to pick the lock to get in (#1). Go to your right. You will have to turn around and choose a narrow passageway. Here's where the bomb is going to be placed (#2). SAVE your game!!
Once you've placed the bomb, you will have to press the use key once again. Hack into the system (#1). It's very important that you don't stay here for too long. Solving the mini-game will allow you to fulfill one of the NSA objectives. Once this is done, leave this area (#2). Make sure that area is clear before moving on. Turn right. Keep going straight.
You will have to approach a small metal box. There's a mini-game here for you to finish (#1). You shouldn't have any problems with these types of actions. Pressing the button will allow you to lower a metal platform. Enter it (#2). After that, Fisher will automatically perform a jump and this mission is going to end.
You will be rewarded with two interesting upgrade items: EMP Grenade - Attachment and Gas Grenade - Attachment.