By Rick Riordan
The people that are at that camp had one of there parents leave them when they were little so they can keep there kids safe. Grover Underwood was one of Percys first friends at Camp Half Blood cause they went to the same school together. Grover is a satyr. Then it comes to Annabeth Chase daughter of athena. She was the one to help out Percy with his problem and the lighting bolt. After what had happen to Luke and his plans and what he tryed to do to the goddess which in clues his dad and others.
This is what Percy is as a god. And his father.
This is the sword of Percy and he uses it to keep him and his friends safe from random creatures that would appear.
This goes to Percy cause he can make water do what ever he wants it to do in his own way and it only works if there is water nearby.