An editor of Space/Aeronautics tackles the very big subject of undersea warfare and its vital importance in our nuclear age. The need for developing an undersea weapon like is recapped, as is the development of submarines, and of undersea research, over the past century. Rickover's story is of course included, as is a brief but factual estimate of Russia's submarine force as compared to ours. New equipment in underwater warfare and exploration --diving bells, undersea vehicles, deep- diving subs -- is also given some attention. Of especial interest however is the author's own experience aboard the nuclear submarine Theodore Roosevelt in the Pacific, followed by further time spent on the surface with a hunter-killer Navy group designed to fight enemy subs. An appendixed list tells how many nuclear subs America has built to date, where they were built, and for what military purposes they are intended. A highly informative work, although somewhat dull in presentation and obviously not intended for a mass audience, of vital interest however to any reader interested in national defense.