Clearly, any good work of fiction is going to use many metaphors and similes as examples of figurative language and aids to their descriptions. Metaphors and similes help create pictures in the reader's mind of what the author is trying to describe by comparing something with an object or a thing that we would not normally think of. By forcing us to see the points of comparison, the metaphors and similes give us a very strong mental image of what is being described.
In Chapter 1, therefore, an excellent simile is used to describe Kit's thoughts at standing on the soil of the land she is voyaging to for the first time:
Her spirits bobbed like the whitecaps in the harbour as the boat pulled away from the black hull of the Dolphin.
Note how this conveys Kit's excitement to be finally close to her end destination and also her sense of expectation.
A metaphor is used later on in the same chapter to describe Kit's anger at the way she is being ignored when Prudence drops her doll into the sea:
When a thin whimper from the child was silenced by a vicious cuff, her anger boiled over.
Of course, anger literally can't "boil over" - her anger is being compared to a pot on a stove that is boiling over to express her sense of outrage.
These are just two examples from the first chapter. Go and have a look for more examples of similes and metaphors in the other chapters. Good luck!