Dirk Pitt,  eco-warrior of the National Underwater & Marine Agency (NUMA), returns for another boys' adventure tale, this one set in the year 2000. Along for the sail are Pitt's roly-poly sidekick, Al Giordino, and father-figure Admiral Sandecker, head of NUMA. As with all of Cussler's novels since he raised the Titanic 20 years ago, the plot is a pip. People and animals are dying mysteriously and in droves on various ocean shores, a catastrophe caused by high-frequency sound waves generated by the ruthless diamond-mining techniques of Australian tycoon Arthur Dorsett, whose fiendish plan is to ruin the diamond cartel and corner the colored gem market. Sometime after Pitt gets on the case, he winds up being cast adrift by Dorsett in a small, leaky boat in the Pacific; also on board are steadfast Al and Dorsett's rebel daughter, Maeve, who provides the novel's love interest.