Everything you need to understand or teach Reef of Death by Paul Zindel.
Reef of Death is a fast-paced adventure populated by mysterious friends and deadly enemies who confront each other in an exotic location. Teenaged PC McPhee thinks he is in for the usual summer of adventure while working for his Uncle Cliff on another one of the uncle's nutty, doomed schemes to get rich, but he is quickly immersed in a frightful life-or-death battle against an array of forces, human and inhuman: greed, a crazed and homicidal scientist, evil magic, and horrifying monsters of the deep. Danger is found at every turn, and not all of PC's companions will survive their encounter with the reef of death.