Board Thread:General Discussion/@comment-25014849-20140627232456/@comment-3146930-20140705153759

Cheese Ausar wrote: The weird thing is, Percy CAN'T EVEN USE HIS POWERS in this situation because there isn't any water.

And the guy still made him 2/3.

Deserts have large amounts of ground water under the surface. Also as shown in The Battle of the Labyrinth, Percy is able to call the sea to him.