You have to go towards the ship and after putting mines, go to the smaller ship (you do not have to go to big ship). go to other opposite side of the ship so that you are first then the small ship then behind that is bigger ship. see carefully and you can see a ope ladder, just adjust a bit so that you and the rope is in straight allignment and then climb but before that order your men to stop as the moment you climb, the guard comming down the stairs will shoot you and alarm will be raised, do not climb fully but climb still leaving 1-2 last stairs, see at the stairs, choose a silent gun, let the guard and officer take their position, now creep up and shoot guard first and then officer, now another guard will come, shoot hi as well and then call your team. choose silent machine gun.

After getting on the ship and killing them will a silent gun go up to the commanders cabin
in there is a person kill him then go in to the next room there is a map which is the
tirpitz plans get it then carry on with the mission and don't through the other door there
is a couple of guard an will shoot and raise the alarm.
Tip: You can use the stealth from training and then you could get much better at doing it.