We've all heard of the movie "Jaws", based on the book of the same title by Peter Benchley. If you like ocean based thrillers, then I highly recommend this book. It's way different than the "Jaws" storyline, and is definitely a book that will draw you in and keep you hooked. To summarize the plot, it's about a mechanical shark based weapon that was created during World War 2 and lost at sea. It appeared on the map years later and due the fact that it was programmed with super advanced AI, once it was powered up and out on it's own, it becomes quite unstoppable. I read this book several years back, but I'm thinking about ordering a copy online and reading it again. I liked the plot of this book a lot more than Jaws. It's definitely more Sci-Fi, but it's at least imaginable as real, unlike some other Sci-Fi stuff.