Watch the intro cutscene as Lara enters the ship.

[Checkpoint] You can switch weapons to Thor's Hammer using the + button. While in combat mode, pressing B shoots bolts of lightning and swinging the Wiimote makes Lara smash the Hammer into the ground for an area attack. Go down the stairs and kill the mercenaries as you make your way to the right side of the boat. Go up the right-hand stairs and through the open door.

[Checkpoint] Go down the stairs and follow the hallway. You'll get to an intersection with a mercenary. Kill him and then go up the left set of stairs and through an open doorway. A cutscene will play and end the level.