An introduction to Par dix-huit mètres de fond, Jacques-Yves Cousteau’s first book.

This article introduces *Par dix-huit mètres de fond*, the first book on diving by Jacques-Yves Cousteau, originally published in French in 1946 and never officially translated into other languages until this English version. The book documents Cousteau's 1942 underwater film and spearfishing expedition near Marseilles during the German occupation, featuring breath-hold diving with Cousteau as cameraman and Frédéric Dumas as diver. It is divided into three sections covering sport, filmmaking, and free diving, and includes stills from the film. The article also details the limited original print runs and historical context, noting Cousteau's acknowledgment of earlier diving pioneers and the book's significance as a foundational work in diving history preceding his later influential publications.