What is the theme and the plot, in i survived the shark attack of

The author clearly has the theme of survival. 

The plot is about a boy that is living away from his parents for a while and he spends that time with his uncle. He and his friends have a lot of fun and the swimming hole until one of his friends play a trick on him ( the shark fin ) and that made a sore patch with all of the boys. The reason that did that was because there was reports of people getting attacked by sharks so it was a touchy subject.  Finally, the main character sets up his own prank and tricks his friend which ultimately makes the friends relationship worse. Finally when they all make up they decide to go for a swim and suddenly a fin cuts through the water and when the kids realized it was a real shark they all started to swim except one because he was frozen in fear so the main character goes back in the water to save his friend. He manages to get his friend out the water but he gets stuck in the clutches of the shark himself. His friends try to pull his out and they finally did but the main character had to go to the hospital because the damage he received to his leg was pretty serious. Well finally in the end everything turns out okay when the main character gets better and survives so there is a happy ending to this story.

I hope my answer helps you. =)

The author's purpose is to be persuasive