A serial killer... A stolen sailboat... And a missing woman

Former U.S. Navy Explosive Ordnance Disposal technician turned commercial diver Ryan Weller is working a salvage job off the Virgin Islands when he hears the familiar voice of Mango Hulsey on the radio, saying his sailboat has been stolen. Immediately, Ryan sets sail for Martinique to help his friend locate his boat.

Billy Ron Sorenson runs a charter service and preys on unsuspecting women. When he's done with them, he sinks their bodies deep into the ocean. But this time he's made some crucial errors. He's stolen the wrong boat, left two dead bodies aboard, and taken a woman hostage.

When a tip leads to the discovery of Mango's boat, he and Ryan find the two dead bodies and are immediately thrust into the hunt for a man the news media has labeled "The Sailboat Slasher" and the woman he's kidnapped. Sorenson's misdeeds catch up with him and he's captured by the police in Trinidad. Unfortunately, they're too late to rescue the girl from the men Billy Ron has sold her to.

Haunted by the fate of the kidnapped woman, Ryan continues searching for her with the aid of the local police and his contacts at Dark Water Research. Can he find her before she disappears forever?