Book 2 in the Gage Finley series of underwater action adventures.
Flush with the success of his finding the treasure of the Scavenger, Gage Finley is stunned to learn that his daughter Niki, known for her exceptional skill as a diver, has been kidnapped and forced to make a series of dives into an underwater cave system looking for a new treasure.
Note: this is the first introduction to Rescue ZULU.