Charlotte Doyle, a thirteen-year-old girl living in the 1800's, is learning to be a proper young lady, dress properly, speak properly, and even eat properly. But all of that changes when she goes on board the Seahawk.
Charlotte Doyle is very wealthy, with beautiful clothes, fair, white skin, and extravagant hats. She is schooled in England and becoming quite a young lady. She boards the Seahawk as just that.
The first change of character that Charlotte has is when she begins to converse with the crew; something a lady of her class was forbidden to do. Soon, she finds herself using their slang words when she talks to them. She begins to accept them for who they are, even though they are way below her class.
Another change is when Captain Jaggery kills Cranick. In the beginning of her voyage, when the captain asked her something, she would say, "Yes sir." But when he tells Charlotte to open the gate so he can throw Cranick's body overboard, but Charlotte refuses. After Mr. Hollybrass opens the gate Captain Jaggery, the man Charlotte relied on, the man she thought of as a second father, decides to beat Zachariah to death. After he whips him a few times, Charlotte takes the whip and whips him in the face. In the beginning of the book, Charlotte wouldn't have ever done that. Therefore, that is another change in character.
The next major change is when Charlotte climbs the royal yard. It is so amazing because she is doing it to become a sailor. She is risking her life, and giving up everything she has lived for. In this part of the book, she showed a lot of perseverance because she didn't give up, and she eventually made it.