Good stuff.
First off, there are a few grammatical problems. Re-read it carefully, and you'll find them. (I like to read it backwards so that I'm seeing it in a different light than I wrote it.) Similarly, you say that this character is from a family of five, but I counted eight...
Other than that, it seems too short. It might just be a prologue, but that doesn't limit its length. The prologue should set this thing up. Really, this seems like it could easily be added to a first chapter. Even then, it's still quite short.
Some tips. Use the beginning to do some more character building, or simply add more physical description. The plane crash was nicely written, but it was kind of abrupt. Set the scene more, and then introduce the dilemma. Add more events as to how they got to this point. There are going to be distinct character interactions before the crash because the character has this family. Does he get along with his parents? Is he close to his brothers? Why or why not? Why does Isabella care for him so much? It seems like these people are going to be central to your character, so allow them to interact.
Just some suggestions. Write some more. I'd like to see how you incorporate this into a pirate story.
