There are a great many interesting and puzzling stories of ships and airplanes disappearing, crashing for no apparent reason, or malfunctioning in strange ways. While many of them could be logically explained or told with a spin that doesn't cover the logical side of things, the sheer amount of examples in the book is noteworthy.
At first, I was impressed by the many well-documented sources. Then, as he began correlating information with hints and stories of UFOs, I paid a little closer attention to the sources. The wrecks and disappearances all come from official records (though some he claims are classified and not available to the public), everything related to aliens comes from the National Inquirer.
It's an entertaining read if you like UFO stories (not so much for me), and interesting to note that there have been significant amount of disappearing planes and boats. What could it mean? Probably nothing.