The part that makes sammy cry is when the girl(/totally forgot her name) blows up the ship with C4, which then kills the main guy behind the whole thing (he was collecting souls for something) and then Katie (a little girl whose soul was trapped on the ship) is directing the girl on where to go to get out safely and as she is swimming to the surface, you see all the other trapped souls swiiming to the surface and circling the sinking ship before they disappear
The very last scene is the girl is being rescued by another cruise ship and as she is being put into an ambulence, she sees the guy that was trapping the souls and the original crew that went to explore the ship get onto the new cruise ship with the gold they found on the old ship (she was the only survivor in the group that explored the ship) and the she starts screaming before the paramedic closes the ambulance doors and then the credits roll
/very confusing, I know