From the flap: "There is only one way to settle the question of the sea-serpents' existence: examine the evidence. And for this task no one is better qualified than Dr. Heuvelmans. His thoroughgoing investigations of over five hundred reported sightings - they come from the Atlantic, Pacific, and Indian oceans and span the years 1693 to 1965 - of animals thought to be sea-serpents are models of scientific probing and precision, with leave the reader convinced that sea-serpents do in fact exist."

The book is in good condition. The dust jacket has small tears and creases along the edges, rubbing, a crease to the spine. The cloth boards show a stain to the front. There's an ownership mark to the first page, and pages 585-612 are bent at the top corner.