The following is a review I wrote of Graham Hancock's 2002 book, Underworld: the Mysterious Origins of Civilization.

Although Graham Hancock's Underworld has been criticized as being "lengthy" or "disorganized," the sites he examines are unified by their contributions to his theory of a more ancient date for civilization than conventionally accepted. Further, the areas of inquiry in this book are essential for any student of mankind's ancient history. Perhaps each could have been a book of its own, but none of them can be ignored: the evidence of man-made ruins at depths of over 75 feet, the mysterious megalithic temples of Malta, the subject of the portolan maps and charts, and the ancient Jomon culture of Japan.

While I believe that the series of events posited in Walt Brown's hydroplate theory better explains both the mechanism of the rise of sea levels and the reason why sites such as Mnajdra on Malta continue to maintain precise alignments with the solstice sunrise after at least 5,000 years, Mr. Hancock has done every student of alternative historical explanation a service by covering these less well-known archaeological treasures as well as the breaking story of the underwater ruins. If critics would like a book that delves into them in a different manner, they should write their own -- Mr. Hancock has certainly provided an excellent jumping-off point and one that belongs in the library of any student of the mystery of mankind's ancient past.

As noted, I believe that the hydroplate theory of Dr. Walt Brown provides a more rigorous explanation for the phenomenon of a rising ocean level, some centuries after the cataclysmic global flood.

As Dr. Brown explains in greater detail in his book, immediately after the flood, the sea levels were significantly lower than they are today, but eventually rose due to the sinking of the continents. I also discuss this mechanism in conjunction with the discovery of underwater ruins in the Mathisen Corollary.

Nevertheless, while disagreeing on the precise details, I am in agreement with Mr. Hancock that the evidence he provides in Underworld clearly indicates a rise in ocean levels within human memory. His analysis of early maps and navigational charts, as well as of the contours of the undersea terrain off the coast of India, the Maldives, Malta, and elsewhere provides powerful confirmation of this important but little-known fact of human history.

Furthermore, his discussion of the megalithic temples of Malta, of aspects of ancient Hindu culture, and his examination of the mysterious Jomon of ancient Japan are all important and lesser-known clues in the search for the truth of mankind's ancient past.

Mr. Hancock is an engaging writer, an expansive intellect, and a courageous promoter of theories that he knows will invite critics and personal attacks. He is not afraid to go in a variety of directions and to correct his previous hypotheses when he uncovers new evidence that cause him to reconsider or revise his conclusions. Because of his many gifts and his ceaseless inquiring, he has become one of the most well-known voices for the idea that mankind's past is dramatically different than previously believed.

While different people examining this broad subject will arrive at different conclusions and will surely have intellectual disagreements over various points, Mr. Hancock should be viewed as a strong ally and in many ways a true pioneer in the cause of bringing mankind closer to the truth of our distant past.