You may find the ship a little confusing at first because of the way Nancy turns. There are basically four areas to the aboveboard ship.
At the prow (the front end), look behind the ship's figurehead to find the lion puzzle.
How do I solve the puzzle behind the figurehead?
In the area where you board, you'll find Elisabet sitting next to a closed door.
How do I open the door behind Elisabet?
In the area up the stairs from Elisabet, you'll find access to the crow's nest and a set of stairs that lead down to the captain's quarters and the hold.
How do I get to the crow's nest?
At the stern (the back end), you'll find the ship's decorative steering wheel and the wheelhouse, where the captain sits to steer the ship.
What am I doing with the steering wheel?