Make sure you arrive at Narvik before April 9. After that it will be really hard to find any enemy ship to take the photo. If got already this part and you need only the 5 merchant ship, is enough to stay at the entrance to the Narvik channel, where it gets a bit narrow.. stay submerged and track with the sonar, you will find a lot of merchants passing that area. But also, make sure all this happens before April 9.
Can't explain how come only me had so hard time to find the damn battleship.. the rest of the mission was so easy, done it in 1 day
