In 1656, a Spanish ship sunk under less than usual circumstances, and certainly not where treasure hunters of today expect. "Where is the final resting place of the Maravilla, along with the gold, silver, and emeralds that she contains?"

A Florida antique dealer, Ted Brewer, quite by accident, finds a sketch with the necessary clues to the old ship's location. Unfortunately for him, there is another person who realizes Brewer is holding the key to a vast fortune, and is willing to brutalize and kill him for that information.

Brewer, however, has insured the safety of his secret by sending half of the sketch to his sister, Jennifer, and the remaining half to his old and trusted Marine Corps buddy, Jake Bottom. Jake, since his retirement from the Corps, has become an expatriated American, living on a houseboat in the Bahamas. His biggest problem, on any given day, is whether or not to just swing in his hammock under the sun, or go sailing on his forty-on foot sloop.

Jake and Jennifer team up to solve the mystery of the two halves of the map, and along with a reprobate friend of his, Mike Flynn, the three sail in search of riches.

Cortez, a Colombian drug lord, has killed for the sketch, and is not hesitant to do so again. With dogged determination, he hunts down the three, as they attempt to keep him blind to their actions. No matter their precautions, Jennifer is nonetheless kidnapped by Cortez and taken prisoner aboard his luxurious yacht.

Jake, who has become completely infatuated with his recent lady companion, and Flynn must somehow retrieve Jennifer, yet not lose their claim to the fortune awaiting them. The plan is complex, with little chance of success.