From the moment you begin Clive Cussler's latest undersea thriller, you know that you're in the hands of a old pro; thus any lingering crotchetiness over the book's stereotypical villains is offset by deft plotting and taut action. Flood Tide details the exploits of Dirk Pitt, Special Projects Director of the National Underwater and Marine Agency, whom Cussler fans already know and love. Judging by this book, "Special Projects" seems to be a euphemism for blowing stuff up. Pitt's worthy adversary is Qin Shang, a Chinese shipping tycoon who is definitely from the Fu Manchu school of management. As part of a nefarious plot to bring the United States to its knees with a flood of illegal immigrants, Qin Shang operates a secluded gulag in rural Washington, which the vacationing (ha!) Pitt stumbles upon. A lot of entertaining mayhem ensues, both on the water and under it. Flood Tide's enthusiastic xenophobia can stick in the throat, and may get in the way for some. But that flaw aside, it delivers the speed and shocks necessary.