* Sword Fighting: Percy enjoys training with his sword, Riptide. He's naturally good at it, and even seems to find a certain enjoyment in it.
* Swimming: Percy's a natural swimmer, likely due to his connection to the sea. This is a skill he utilizes throughout the book, and it suggests he enjoys being in the water.
* Reading: Percy mentions reading Greek mythology and enjoying learning about the gods. He even uses his knowledge of the myths to his advantage during his quest.
* Hanging out with friends: He values his friendship with Annabeth and Grover and enjoys their company.
Overall, Percy's time is mostly taken up by his journey and his training. His hobbies are mostly practical skills he needs for survival.
It's worth noting that as the series progresses, Percy develops more hobbies and interests, like playing Capture the Flag with his friends at Camp Half-Blood. But in *The Lightning Thief*, he's still figuring out his identity and place in the world.