In the late nineteen thirties the author, no longer able to endure a dull clerkship in London, inaugurated a small fishing business on the west coast of Scotland. His prey was the basking shark---thirty foot junior leviathan weighing as much as six tons and often dwarfing the boat which pursues it. How true this disparity of size is, the author discovered after harpooning such a shark from a dinghy. The fish dragged him a hundred miles out into the Atlantic. But soon he learned the ways of the giant fish, gaining knowledge which contradicts most popular writing concerning it. In fact it is just this knowledge which enlivens a dull text---along with many excellent pictures of the busy sharks. Interesting, informative, but only for those whose marine enthusiasm goes deeper than a fathom or so.